Question

Find the cost of painting an open rectangular tank of dimensions 4m×2.5m×5m at the rate of 5.50perm²

Answer 1

Area that should be painted,

= Lateral surcace area + area of base.

= 2(l+b)h + l×b.

= 2lh+2bh+lb.

= 2(4)(2.5)+2(2.5)(2.5)+(4)(2.5)

= 20+12.5+10

= 42.5 m².

Now,

Cost of painting 1 m² = 5.50

Therefore cost of painting 42.5 m²

= 5.5×42.5

= 232.75

☆ Therefore cost of painting is 232.75 .