Question

Find the cost of painting the all round outer surface of a box with lid 60 cm long 40cm wide and 30cm high at 50p per 20cmsqure

Answer 1

hi friend
here's your answer looking for

TOTAL SURFACE AREA =

$2(lb + bh + lh) \\ \\ = 2(60 \times 40 + 40 \times 30 + 30 \times 60) \\ \\ = 2(2400 + 1200 + 1800) \\ \\ = 2(5400) \\ \\ = 10800 {cm}^{2}$

cost of painting =

$\frac{10800}{20} \times .50 \\ \\ = rs 270$
hope you are satisfied with my answer