Total value of coins = Rs. 90
Proportion of number of 50 paise, 25 paise and 10 paise coins = 2 : 3 : 5
Proportion of their values =2×50:3×25:5×10
=100:75:50
Sum of the proportion =100+75+50=225
∴ Values of 25 paise coins =Rs.90225×75=Rs.30
Hence, number of 25 coins =30×4=120.