Let us consider,
Number of 25-paisa coins = x and
Number 50-paisa coins = y
Total number of coins = 50
and total amount = ₹ 19.50 or 1950 paisa
x + y = 50 …(1)
25x + 50y = 1950
x + 2y = 78 …(2)
Subtracting (1) from (2),
y = 28
And, x = 50 – y = 50 – 28 = 22
Number of 25-paisa coins = 22
and 50-paisa coins = 28