Charlie has 60 nickels and dimes whose value was $5. How many of each kind of coin did he have?

Question

60 nickels and dimes whose value was $5. How many of each kind of coin did he have?

Answer 1

Let N = number of nickels   D = number of dimes

 

1)  N + D = 60    (or N = 60 - D)

 

2) $0.05*N + $0.10*D = $5      ( or 5 cents per nickel x # nickels + 10 cents per dime x # dimes = 500 cents)

 

You have 2 equations and 2 unknowns

 

Substitute equation 1) into equation 2) and solve for D:

 

$0.05*(60 - D) + $0.10*D = $5   (combine like terms)

 

$3 - $0.05*D  + $0.10*D  =  $5

 

$0.05*D = $2

 

D = $2/$0.05 = 40 dimes

 

 

N = 60 -D  = 60 - 40 = 20 nickels