Question

A collection of coins has value of 64 cents. There are two more nickels than dimes and three times as many pennies as dimes. How many of each kind of coin are there?

Answer 1

Let d = number of dimes

Let n = number of nickels

Let p = number of pennies

As given, there are two more nickels than dimes and three times as many pennies as dimes:

$d+2=n$

$3d=p$

$0.10d+0.05n+0.01p=0.64$

Plug in the value to find d

$0.10d+0.05(d+2)+0.01(3d)=0.64$

$0.10d+0.05d+0.1+0.03d=0.64$

$0.18d=0.54$

$d=3$

As p=3d

p=$3\times3=9$

As n=d+2    

$n=3+2=5$

Hence, there are 5 nickels, 3 dimes and 9 pennies.