Question

Ricky has 16 coins consisting of P5 & P1 coins amounting to P44. How many of each kind does he have?

Answer 1

number of P5's --- x
number of P1's --- y

x+y = 16
5x + 1y = 44
subtract them:
4x = 28
x = 7
y = 9

check:
5(7) + 1(9) = 44