Question

. A blackboard is 27 dm 7cm long and
21 dm 5 cm broad. What will be the cost of
painting it at the rate of 75 paise per square
centimetre?
I need full answer​

Answer 1

Answer:

Rs. 712425

Step-by-step explanation:

A black board is 17 dm 7 cm long and 11 dm 5 cm broad.

Here..

Length of board = 17 × 10 + 7

= 170 + 7

= 177 cm

Breadth of board = 11 × 10 + 5

= 110 + 5

= 115 cm

Now,

Area of blackboard = Area of rectangle

Area of rectangle = length × breadth

Substitute the known values in above formula

=> 177 × 115

=> 20355 cm²

Now,

Cost of painting the blackboard at the rate of 35 paise per cm²

=> 20355 × 35

=> Rs. 712425