Question

A certain sum of money is made up of Re. 1, 50 paise and 25 paise coins. The ratio of the number of these coins is 2.5 : 3 : 4. Then, 3/5th of the Re. 1 coins are changed to 50 paise and 25 paise coins, such that the ratio of the total number of these coins in the same order became 1 : 2. Now, half of the 50 paise coins are changed to Re. 1 coins and all the 25 paise coins are changed to Re. 1 and 50 paise coins in the ratio 7: 4. What is the ratio of the Re. 1 and 50 paise coins at the end of the conversions?​

Answer 1

Let the common ratio be x.

Then, the total number of 1-rupee coins = 2.5x

Then, the total number of 50-paise coins = 3x

Then, the total number of 25-paise coins = 4x

Now,

Given that total number of coins add up to 210.

= > 2.5x + 0.5 * 3x + 0.25 * 4x = 210

= > 2.5x + 1.5x + 1x = 210

= > 5x = 210

= > x = 42.

Number of 50-paise would be = 3(42)

                                                  = 126.

Therefore the total number of 50 paisa coins = 126.