Q21 of 54 Page 77

A man has only 20 paisa coins and 25 paisa coins in his purse. If he has 50 coins in all totaling rupees 11.25 how many coins of each does he have?

Let the number of 20 paisa coins be x and number of 25 paisa coins be y.

Total coins = 50


∴ x + y = 50


x = 50 – y ……(1)


(Number of 20 paisa coins × 20) + (Number of 25 paisa coins × 25) = Total money


1 rupee = 100 paisa


11.25 rupee = 11.25×100 paisa


= 1125 paisa


20x + 25y = 1125 ……(2) (As the person has total 1125 paisa)


Substitute value of x from (1) in (2)


20x + 25y = 1125


20(50 – y) + 25y = 1125


1000 – 20y + 25y = 1125


5y = 1125 – 1000


5y = 125



y = 25


x = 50 – y


x = 50 – 25


x = 25


∴ He has 25 coins of 20 paisa and 25 paisa.


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