Extra Curriculum Support

Sec A

1.A fan is listed at ₹ 1500 and a discount of 20% is offered on the list price. What additional discount must be offered to the customer to bring the net price to ₹ 1104 ?

(a) 15% (b) 12%

(c) 10% (d) 8%

2.Assertion (A): On ₹ 160000 for one year at the rate of 20% per annum, if the interest is compounded quarterly. Then the compound interest will be ₹ 34481.

Reason (R): Here P = ₹ 160000, R = 5%, n = 4.

(a) Both A and R are true and R is the correct explanation of A.

(b) Both A and R are true but R is not the correct explanation of A.

(c) A is true but R is false.

(d) A is false but R is true.

3.State True or False: The single discount which is equal to two successive discounts 20% and 10% is 30%.

4.The list price of a frock is Rs 220. A discount of 20% is announced on sales. What is the sale price?

(a) Rs 122 (b) Rs 154

(c) Rs 176 (d) Rs 144

5.The difference of compounded and simple interest on any amount at 4% annual rate of interest for 2 years ₹ is 4. Find the principal ?

(a) ₹2500 (b) ₹2000

(c) ₹2400 (d) ₹2600

6.Find C.I. on Rs 20,000 for 3 years at 20% per annum compounded annually.

(a) Rs 14,000 (b) Rs 15,000

(c) None of these (d) Rs 14,560

7.The cost of a vehicle is ₹ 1,75, 000. If its value depreciates at the rate of 20% per annum, then the total depreciation after 3 years was:

(a) ₹ 82,500 (b) ₹ 86,400

(c) ₹ 85,400 (d) ₹ 84,500

8.A football team won 10 matches out of the total number of matches they played. If their win percentage was 40%, then how many matches did they play in all ?

(a) 26 (b) 30

(c) 25 (d) 20

9.A scooter was bought at Rs 42,000. Its value depreciated at the rate of 8% per annum. Find its value after one year.

(a) Rs 38,640 (b) Rs 35,640

(c) Rs 40,640 (d) None of these

10.The price of a TV is Rs 13,000. The sales tax charged on it is at the rate of 12%. Find the amount that Vinod will have to pay if he buys it.

(a) Rs 13,560 (b) None of these

(c) Rs 14,560 (d) Rs 15,560

Sec B

1.The marked price of a DVD is ₹4500. A shopkeeper allows two successive discounts of 10% and 5% by the force of a customer. Find the selling price of the customer after two discounts are given.

2.A scooter was bought at ₹42,000. Its value depreciated at the rate of 8% per annum. Find its value after one year.

3.The population of a place increased to 54,000 in 2003 at a rate of 5% per annum. what would be its population in 2005.

4.If Chameli had ₹ 600 left after spending 75% of her money, how much did she have in the beginning?

5.The price of a TV is ₹13000. The sales tax charged on it is at the rate of 12%. Find the amount that Vinod will have to pay if he buys it.

Sec C

1.Given, principal = ₹40000, rate of interest = 8% per annum compounded annually. Find:

(i) Interest if period is one year.

(ii) Principal for Ilnd year.

(iii) Interest for Ilnd year.

(iv) Amount if period is two year.

2.Raheem runs a readymade garment shop. He mark the garments at such a price that even after allowing a discount of 12.5%, gain a profit of 25%. Find the marked price of a jacket which costs him Rs. 2,100.

3.What price should a shopkeeper mark on article that costs him ₹600 to gain 20%, after allowing a discount of 10% ?

Sec D

1.Simran went to a shop which gives 20% discount the following items during sale.

(i) Discount is equal to Marked price - ?

(ii) Find the sale price of a dress marked at ₹ 1200 ?

(a) ₹ 960 (b) ₹ 1000

(c) ₹ 1200 (d) ₹ 900

(iii) How much discount she will get on pair of shoes marked at ₹ 750 ?

(a) 250 (b) 200

(c) 100 (d) 150

(iv) Find the sale price of a bag marked at ₹ 2000 ?

(a) ₹ 1800 (b) ₹ 400

(c) ₹ 1500 (d) ₹ 1600

(v) Her total saving in the shopping is ₹ 800.

(a) True (b) False

Problem 1

A group of students decide to reduce the use of plastic in their school by 30%. If the school used 1200 plastic bottles last year, how many bottles should they aim to use this year? How does this initiative show the students' concern for the environment?

Problem 2

Neha helps her grandparents by managing their finances. Her grandparents receive a pension of Rs. 20,000 per month. Neha helps them invest 15% of it in a savings account that offers 6% annual interest. How much will her grandparents earn from this investment in a year? What value of care and financial planning does Neha display?

Problem 3

Meena wants to donate to an orphanage. She plans to save 25% of her monthly allowance of Rs. 1600. How much will she save in 6 months? What value does Meena's decision to donate and save demonstrate?

Q1

A bacteria culture grows at a rate of 10% per hour. After 5 hours, the population is found to be 7,200.

(i) What was the initial population of the bacteria ?

(ii) How long will it take for the population to triple from its initial value ?

(iii) If the bacteria culture starts to decay at 5% per hour after a certain point, how does that affect the future population ?

Q2

A man wants to invest Rs. 20,000 for 5 years. He has two options:

Option A: A bank offers him 5% interest, compounded annually.

Option B: Another bank offers him 7% simple interest.

(i) Calculate the total amount he will get under both options after 5 years.

(ii) Which option is more beneficial and why?

(iii) If the man wishes to invest for 10 years, how does the comparison between the two options change ?

Q3

A trader mixes two types of rice: one costing Rs. 30 per kg and another costing Rs. 50 per kg. He sells the mixture at Rs. 45 per kg. If he mixes them in the ratio 2:3 :

(i) Find the cost price of the mixture.

(ii) Calculate the profit or loss percentage.

(iii) What would happen to the profit or loss percentage if the selling price was Rs. 40 per kg instead ?

Q4

A shopkeeper buys two sets of chairs. He sells one set at a profit of 20% and the other at a loss of 15%. The total cost price of the two sets is Rs. 50,000, and the selling price is Rs. 53,000. Find:

(i) The cost price of each set.

(ii) What would be the profit or loss percentage if both sets were sold at the same price ?

(iii) Why do different profit and loss percentages impact overall profit/loss differently ?

Questions

1.Sita is practicing basket ball. She has managed to score 32 baskets in 35 attempts. What is her success rate in per centage?

2.The per cent of pure gold in 14 carat gold is about 58.3%. A 14 carat gold ring weighs 7.6 grams. How many grams of pure gold are in the ring?

3.A student used the proportion n100 = 532 to find 5% of 32. What did the student do wrong?

4.During school hours, Neha finished 73% of her homework and Minakshi completed 5/8 of her homework. Who must finish a greater per cent of homework?

5.With the decrease in prices of tea by 15% Tonu, the chaiwallah, was able to buy 2 kg more of tea with the same Rs 45 that he spent each month on buying tea leaves for his chai shop. What was the reduced price of tea? What was the original price of tea?

6.A store is having a 25% discount sale. Sheela has a Rs 50 gift voucher and wants to use it to buy a board game marked for Rs 320. She is not sure how to calculate the concession she will get. The sales clerk has suggested two ways to calculate the amount payable.

Method 1: Subtract Rs 50 from the price and take 25% off the resulting price.

Method 2: Take 25% off the original price and then subtract Rs 50.

(a) Do you think both the methods will give the same result? If not, predict which method will be beneficial for her.

(b) For each method, calculate the amount Sheela would have to pay. Show your work.

(c) Which method do you think stores actually use? Why?

7.Brinda purchased 18 coats at the rate of Rs 1,500 each and sold them at a profit of 6%. If customer is to pay sales tax at the rate of 4%, how much will one coat cost to the customer and what will be the total profit earned by Brinda after selling all coats?

8.Ashima sold two coolers for Rs 3,990 each. On selling one cooler she gained 5% and on selling the the other she suffered a loss of 5%. Find her overall gain or loss % in whole transaction.

9.Find the difference between Compound Interest and Simple Interest on Rs 45,000 at 12% per annum for 5 years.

10.If principal = Rs 1,00,000. rate of interest = 10% compounded half yearly. Find:

(i) Interest for 6 months.

(ii) Amount after 6 months.

(iii) Interest for next 6 months.

(iv) Amount after one year.

11.In 1975, the consumption of water for human use was about 3850 cu.km/year. It increased to about 6000 cu.km/year in the year 2000. Find the per cent increase in the consumption of water from 1975 to 2000. Also, find the annual per cent increase in consumption (assuming water consumption increases uniformly).

Questions

1.To calculate the growth of a bacteria if the rate of growth is known, the formula for calculation of amount in compound interest can be used.

2.Additional expenses made after buying an article are included in the cost price and are known as Value Added Tax.

3.Compound interest is the interest calculated on the previous year’s amount.

4.C.P. = M.P. – Discount.

5.A man purchased a bicycle for Rs 1,040 and sold it for Rs 800. His gain per cent is 30%.

6.Simple interest on a given amount is always less than or equal to the compound interest on the same amount for the same time period and at the same rate of interest per annum.

7.Three times a number is 200% increase in the number, then onethird of the same number is 200% decrease in the number.

8.If the discount of Rs y is available on the marked price of Rs x, then the discount percent is xy × 100 %.

9.The compound interest on a sum of Rs P for T years at R % per annum compounded annually is given by the formula P(1 + (R/100)).

10.In case of gain, S.P. = 100+gain%×C.P.100

11.In case of loss, C.P. = 100×S.P.100+loss%

Questions

1.Suppose for the principal P, rate R% and time T, the simple interest is S and compound interest is C. Consider the possibilities.

(i) C > S (ii) C = S (iii) C < S

Then:

(a) only (i) is correct.

(b) either (i) or (ii) is correct.

(c) either (ii) or (iii) is correct.

(d) only (iii) is correct.

2.Suppose a certain sum doubles in 2 years at r % rate of simple interest per annum or at R% rate of interest per annum compounded annually. We have:

(a) r < R (b) R < r

(c) R = r (d) can’t be decided

3.The compound interest on Rs 50,000 at 4% per annum for 2 years compounded annually is:

(a) Rs 4,000 (b) Rs 4,080

(c) Rs 4,280 (d) Rs 4,050

4.For calculation of interest compounded half yearly, keeping the principal same, which one of the following is true.

(a) Double the given annual rate and half the given number of years.

(b) Double the given annual rate as well as the given number of years.

(c) Half the given annual rate as well as the given number of years.

(d) Half the given annual rate and double the given number of years.

5.Ashima took a loan of Rs 1,00,000 at 12% p.a. compounded halfyearly. She paid Rs 1,12,360. If 1.062 is equal to 1.1236, then the period for which she took the loan is:

(a) 2 years (b) 1 year

(c) 6 months (d) 112 years

6.A bought a tape recorder for Rs 8,000 and sold it to B. B in turn sold it to C, each earning a profit of 20%. Which of the following is true:

(a) A and B earn the same profit.

(b) A earns more profit than B.

(c) A earns less profit than B.

(d) Cannot be decided.

7.A sum is taken for two years at 16% p.a. If interest is compounded after every three months, the number of times for which interest is charged in 2 years is:

(a) 8 (b) 4 (c) 6 (d) 9

8.Avinash bought an electric iron for Rs 900 and sold it at a gain of 10%. He sold another electric iron at 5% loss which was bought Rs 1200. On the transaction he has a:

(a) Profit of Rs 75 (b) Loss of Rs 75

(c) Profit of Rs 30 (d) Loss of Rs 30

9.40% of [100 – 20% of 300] is equal to:

(a) 20 (b) 16

(c) 140 (d) 64

Questions

1.? is charged on the sale of an item by the government and is added to the bill amount.

2.Sales tax = tax % of ?.

3.The time period after which the interest is added each time to form a new principal is called the ?.

4.? expenses are the additional expenses incurred by a buyer for an item over and above its cost of purchase.

5.The discount on an item for sale is calculated on the ?.

6.When principal P is compounded semi-annually at r % per annum for t years, then Amount = ?.

7.Percentages are ? to fractions with ? equal to 100.

8.? is a reduction on the marked price of the article.

9.Increase of a number from 150 to 162 is equal to increase of ? per cent.

10.Discount = Discount % of ?.

Q1

A school organized a fundraising event to support underprivileged children. The school set a target of raising Rs. 50,000. At the end of the event, they found that they had collected Rs. 47,500. The principal announced that the school had achieved 95% of its target.

(i) By how much did the school fall short of its target ?

(ii) If the school plans to organize a similar event next year with an expected 10% increase in contributions, what should be the target for next year ?

(iii) What values are being demonstrated by the students and the school community ?

Q2

A small business owner buys clothes in bulk for Rs. 10,000. He sells them at a 15% profit. After a week, he decides to offer a 10% discount on the selling price to attract more customers.

(i) What is the selling price of the clothes after a 15% profit ?

(ii) What will be the selling price after the 10% discount on the new price ?

(iii) How does this case highlight the importance of decision-making and customer care in business ?

Q3

Rahul bought a cricket bat from a sports shop. The marked price of the bat was Rs. 1800, but the shop was offering a 20% discount on all sports equipment. Rahul also had a coupon that offered an additional 5% discount on the discounted price.

(i) What is the price of the bat after the first discount of 20% ?

(ii) What will be the final price after applying the additional 5% discount ?

(iii) What values are promoted by the idea of offering discounts on sports equipment for students ?