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.
Deepak BoraNewbie
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