9. Four mark exercise problems I

A sweet is in the shape of rhombus whose diagonals are given as \(4 \ cm\) and \(5 \ cm\). The surface of the sweet should be covered by an aluminium foil. Find the cost of aluminium foil used for \(400\) such sweets at the rate of \(₹7\) per \(100 \ sq. \ cm\).

 

Answer:

 

The cost of aluminium foil \(= ₹\)