Answer:
number of 50c = x
number of 20c = y
total coins 40
x +y = 40 ------(1)
0.5x + 0.2y = 16.10 ------(2)
from (1) => x = 40 - y
substitute x in (2)
0.5(40 -y) + 0.2y = 16.10
20 - 0.5y + 0.2y = 16.10
-0.3y = -3.9
y = 13
from (1) => x = 27
Answer: number of 50c = 27 coins
