Question:
Aruna has only ₹ 1 and ₹ 2 coins with her. If the total number of coins that she has is 50 and the amount of money with her is ₹ 75, then the number
of ₹ 1 and ₹ 2 coins are, respectively
(a) 35 and 15
(b) 35 and 20
(c) 15 and 35
(d) 25 and 25
Solution:
(d) Let number of ₹ 1 coins = x
and number of ₹ 2 coins = y
Now, by given conditions x+y=50 …(i)
Also, x×1+y×2=75
⇒ x + 2y = 75 …(ii)
On subtracting Eq. (i) from Eq. (ii), we get
(x + 2y) – (x + y) = 75 – 50
⇒ y = 25
When y = 25, then x = 25