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प्रश्न
A lady has only 50-paisa coins and 25-paisa coins in her purse. If she has 50 coins in all totaling Rs.19.50, how many coins of each kind does she have?
उत्तर
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 respectively
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