Question

the inside of an open metal box of internal dimensions 25cm *18cm* 15cm is lined with paper . find the area of the paper required ?​

Answer 1

 2 x 15 x 18 +  2 x 15 x 25 +  18 x 25 = 1740

 

If lid is included, then add another 18 x 25 = 450,

so 1740 + 450 = 2190