Question

The length of a rectangular blackboardis three times its width. If the width is 1.5m, find its area. Also, find the cost of painting the blackboard at the rate of ₹4 per sq.m.​

Answer 1

Let length be x and width is 1.5m

Acc. to ques, length is thrice the width...

Hence, length=3 x 1.5m = 4.5m

Area of blackboard= length x breadth

(4.5 x 1.5)m^2

Cost of painting the blackboard= ₹4 per sq.m.​

= Rs. (4 x 4.5 x 1.5)

= Rs. 27

Hope it helped u.....

Answer 2

Let the length of a rectangular blackboard = 3 × width

( weight of a rectangular blackboard = 1.5 ) so,

length would be 3× 1.5 = 4.5

area of the rectangular blackboard = L× B

= 4.5 × 1.5

= 6.75 sq.m.

and the cost of painting the blackboard at the rate of ₹4 per sq.m.

= 6.75 × ₹4

= ₹27.00

= ₹ 27.