5.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 \(m^2\) of area is painted.How many cans of paint will she need to paint the room?

Given, l = 15 m, b = 10 m and h = 7 m
Area of the paint in one can = \(100 m^2\)

So,Surface area of a cuboidal hall without bottom = Total surface area – Area of base

\(= 2 (lb + bh + hl) – lb\)

\(= 2 (15 \times 10 + 10 \times 7 + 7 \times 15) – 15 \times 10\)

\(= 2(150 + 70 + 105) – 150\)

\(= 2 (325) – 150\)

\(= 650 – 150= 500 m^2\)

Therefore, the number of cans required =\(\frac { 500 }{ 100 }= 5 cans\).