Question

A box without lid is made by wood of thickness 3cm its outer dimension are 146 cm into 116 cm into 83 cm find the cost of painting the internal surface of the box @ mm square cm

Answer 1

First subtract 3 from the outer dimension and then find the are by l×b×h but subtract the lids length .
We have to subtract because the lid is not to be counted and in the formula of are the lid comes











Hope it helps you.......