SOLUTION: Rachel’s piggy bank consists of P10 and P5 coins only. If there are 75 coins worth P450, how many coins of each kind does she have?
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Question 1011651: Rachel’s piggy bank consists of P10 and P5 coins only. If there are 75 coins worth P450, how many coins of each kind does she have? Answer by Cromlix(4381) (Show Source):
You can put this solution on YOUR website! Hi there,
Make P5 coins = x
Make P10 coins = y
x + y = 75.......(1)
5x + 10y = 450....(2)
Multiply (1) by 10
10x + 10y = 750....(1)
5x + 10y = 450.....(2)
Subtract (2) from (1)
5x .....= 300
x.......= 60
Substitute x = 60 into (1)
x + y = 75.......(1)
60 + y = 75
y = 75 - 60
y = 15
You have 60 x P5 coins
and 15 x P10 coins.
Hope this helps :-)