(d) Let the no. of Rs.1 coins = x
and the no. of Rs.2 coins = y
According to the question:
x + y = 50 . ... (i)
x.1 + 2. y = 75 . ... (ii)
on solving (i) and (ii), we get
2y – y = 75 – 50
⇒ y = 25
put value of y in equation (i), we get
x = 50 – y
= 50 – 25 = 25
Hence, number of Rs.1 and Rs. 2 coins are 25 and 25 respectively.