Note that there are 100 paise in one rupee.
Let x be the number of 10 paise coins.
Then the number of 25 paise coins is 3x.
The number of 50 paise coins is 3x + 5
The total amount of money in the bag is 120 Rupees, which is equal to 12,000 paise. We can set up an equation.
10x + 25(3x) + 50(3x+5) = 12,000
10x + 75x + 150x + 250 = 12,000
235x = 11,750
x = 11,750 / 235
x = 50
The number of 10 paise coins in the bag is 50.
