Question

Calvin has $8.80 in pennies and nickels. If there are twice as many nickels as pennies, how many pennies and nickels does Calvin have?

Answer 1

Let x be the no. of pennies and let y be the no. of nickles

Answer 2

Set up equations using these variables:

Equation 1: y=2x
Equation 2: 0.01x + 0.5y = 8.80

Now, you solve:

Substiture y=2x in equation 2:

= 0.01x + 0.5(2x) = 8.80
= 0.01x + 0.10x = 8.80
= 0.11x=8.80
x = 8.80/0.11 = 80
Therefore, x=80.

Substiture x=8 in equation 1:
y=2(80) = 160
Therefore y=160.

Hence, there are 80 pennies and 160 nickels.