Hridaya opened her piggy bank and found coins of denomination ₹1, ₹2, ₹5 and ₹10 in the ratio 10 : 5 : 2 : 1. If there are 72 coins in all, then how much money (in ₹) was there in the piggy bank in the form of coins?

160

Denominations        ₹1  :  ₹2  :  ₹5  :  ₹10

No. of coins            10  :    5  :    2  :  1    ⇒ 18R = 72 

                                                                     R = 4

Total money = denomination x no. of coins 

                  = (1 x 40) + (2 x 20) + (5 x 8) + (10 x 4)

                  = 40 + 40 + 40 + 40 = 160