In a bag, there are coins of 25 p, 10 p and 5 p in the ratio of 2 : 3 : 5 respectively. If the value of all the coins is Rs 5.25, then how many 5 p coins are there in the bag?

In a bag, there are coins of 25 p, 10 p and 5 p in the ratio of 2 : 3 : 5 respectively.

Let's assume the number of 25 p, 10 p and 5 p coins are 2y, 3y and 5y respectively.

If the value of all the coins is Rs 5.25.

$$\frac{25}{100}\times2y+\frac{10}{100}\times3y+\frac{5}{100}\times5y\ =\ 5.25$$ [Here 100 is divided because the value of each coin should be in the same unit.]

$$0.25\times2y+0.1\times3y+0.05\times5y\ =\ 5.25$$

$$0.5y+0.3y+0.25y\ =\ 5.25$$

$$1.05y\ =\ 5.25$$

y = 5

Number of 5 p coins in the bag = 5y

= $$5\times5$$

= 25