Exercise 3.1

Question 1

1. How will you describe the position of a table lamp on your study table to another person?

Sol

Solution:

Say, the table dimensions are: Length = 80 cm and Width = 40 cm.

Assumption: If the lamp is at center of the table and the x-axis is along the length of the table and the y-axis, we can calculate the position of the lamp as:

Position of lamp = (2,2) = (,)

Question 2

2. (Street Plan) : A city has two main roads which cross each other at the centre of the city. These two roads are along the North-South direction and East-West direction.

All the other streets of the city run parallel to these roads and are 200 m apart. There are 5 streets in each direction. Using 1cm = 200 m, draw a model of the city on your notebook. Represent the roads/streets by single lines.There are many cross- streets in your model. A particular cross-street is made by two streets, one running in the North - South direction and another in the East - West direction. Each cross street is referred to in the following manner : If the 2nd street running in the North - South direction and 5th in the East - West direction meet at some crossing, then we will call this cross-street (2, 5). Using this convention, find:

(i) How many cross - streets can be referred to as (4, 3).

(ii) How many cross - streets can be referred to as (3, 4).

Sol

Solution: We can represent the given problem as shownn. From the figure given, we can see that:

(i) Only one cross-street can be referred to as (4, 3).

(ii) Only one cross-street can be referred to as (3, 4).