# Daniel is painting the walls and ceiling of a cuboidal hall with length, breadth and height of 15 m, 10 m and 7 m respectively. From each can of paint 100 m² of area is painted. How many cans of paint will she need to paint the room?

**Solution:**

Since the hall is cuboidal in shape, the walls of the hall make the lateral surface area of a cuboid.

The total surface area of the hall to be painted will be the sum of the lateral surface area of four walls and sum of the area of the ceiling.

Length of the hall l = 15 m

Breadth of the hall b = 10 m

Height of the hall h = 7 m

Lateral surface area of four walls = (h × l + h × b + h × l + h × b) = 2(hl + hb)

= 2(7 × 15 + 7 × 10) m²

= 2(105 + 70) m²

= 350 m²

Area of the ceiling = l × b

= 15 × 10 = 150 m²

Area of the hall to be painted = Lateral surface area of walls + Area of the ceiling.

= 350 m² + 150 m² = 500 m²

It is given that from each can 100 m² area can be painted.

Number of cans required to paint an area of 500 m² = 500/100 = 5 cans

**Video Solution:**

## Daniel is painting the walls and ceiling of a cuboidal hall with length, breadth and height of 15 m, 10 m and 7 m respectively. From each can of paint 100 m² of area is painted. How many cans of paint will she need to paint the room?

### Maths NCERT Solutions Class 8 - Chapter 11 Exercise 11.3 Question 5

**Summary:**

Daniel is painting the walls and ceiling of a cuboidal hall with length, breadth and height of 15 m, 10 m and 7 m respectively. From each can of paint 100 m² of area is painted. 5 cans will be required to paint the walls and the ceiling of the cuboidal hall.