ICSE & CBSE Board Question Based on Linear Equations in two Variables of RS Aggarwal

Here the total number of 25-paisa and 20-paisa coins together and their sum is given. you have to find the number of each type of paisa.

This is the Question Number 3 Of Exercise 3E of RS Aggarwal Solution.

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# A lady has only 25-paisa and 50-paisa coins in her purse. If she has coins in all totalling RS19.50, how many coins of each kind does she have?

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Let x and y be the number of 50-paisa and 25-paisa coins respectively.

Then

x + y = 50 ……….(i)

0.5x + 0.25y = 19.50 ………(ii)

Multiplying (ii) by 2

and subtracting it from (i),

we get 0.5y = 50 – 39

⇒ y = 11/0.5 = 22

Subtracting

y = 22 in (i)

we get x + 22 = 50

⇒ x = 50 – 22 = 28

Hence, the number of 25-paisa and 50-paisa coins is 22 and 28