Anna has 50 coins in her piggy bank. She notices that she only has dimes and pennies. If she has exa

Anna has 50 coins in her piggy bank. She notices that she only has dimes and pennies. If she has exactly four times as many pennies as dimes, how many pennies are in her piggy bank?

Let d be the number of dimes, and p be the number of pennies. We're given:

1. d + p = 50
2. p = 4d

Substitute (2) into (1)
d + 4d = 50

Type that equation into our search engine. We get:
d = 10

Now substitute this into Equation (2):
p = 4(10)
p = 40