Question

the Length, breadth, height of a room are 5m ,4m and 3M respectively. find the cost of white washing the walls of the room and ceiling at the rate of Rs 7. 50 per metre square.​

Answer 1

Here,

l=5m

b=4m

h=3m

t.s.a of cuboid=2(lb+bh+hl)-lb

=2(5×4+4×3+3×5)-5×4

=2(47)-20

=98-20

=78metre square

cost of white washing=78×rs.7.50

=Rs.585

hence, the ans. is rs.585

Hope it helps!