A playground measures 300 m × 170 m . Find the cost of planting grass on this at the rate of ₹ 80 per hectare.

Given, The measures of playground is 300 m × 170 m . ⇒ Length = 300 m and breadth = 170 m We know that, Area of rectangle = length × breadth = 300 × 170 = 51000 m 2 Cost for planting grass is ₹ 80 per hectare. As 1 hectare = 10000 m 2 ⇒ 51000 m 2 = 51000 10000 hectare = 5 . 1 hectare Therefore, the cost of planting grass on the ground = Area of the ground × cost per hectare = ₹ 5 . 1 × 80 = ₹ 408 Hence, the cost of planting grass on the ground is ₹ 408 .

A tile measures 10 cm × 10 cm . How many such tiles are required to cover a wall of 4 m × 2 . 5 m ?

Given: In a wall Length of the wall = 4 m and breadth of the wall = 2 . 5 m Size of each tile = 10 cm × 10 cm We need to find the number of the tiles covering the wall. Length of the wall = 4 m = ( 4 × 100 ) cm = 400 cm The breadth of the wall = 2 . 5 m = ( 2 . 5 × 100 ) cm = 250 cm Area of the wall = Length × Breadth = ( 400 × 250 ) sq cm Area of each tile = ( 10 × 10 ) sq cm Number of tiles required for covering the wall = Area of the wall Area of each tile = 400 × 250 10 × 10 = 1000 Thus, the number of tiles required to cover a wall is 1000 .