Question

a laboratory is 9m long, 8m broad and 6m high it has 2 doors each of size 3 m * 1.5m and four windows each of size 1.5m *1 m find the cost of whitewashing the walls of the laboratory at the rate of rs 1.75 per sq. m.

Answer 1

hope the calculations are right

Answer 2

Here we need to find the lateral surface area and substraction the area occupied by doors and windows
so,the formula is [2(lb+bh+hb)]-[(area of doors)+(area of windows)]
that is , (204)-(15)
=189

cost=189*1.75
=33015