Question

Jacob puts all his pennies and nickels in his piggy bank. e has saved up a total of 474 couns. altogether, there is a total of $11.22 in his bank. how many pennies and how many nickels does he have in his piggy bank?

Answer 1

Penny = 0.01

Nickel = 0.05

He saved up a total of 474 coins

x + y = 474

Where:

x = number of pennies

y= number of nickels

There is a total of 11.22 in his bank:

0.01x + 0.05y = 11.22

We have the system of equations:

x + y = 474 (a)

0.01x + 0.05y = 11.22 (b)

Solve (a) for x :

x = 474-y

Replace x on (b) and solve for y:

0.01 (474-y) + 0.05y = 11.22

4.74 -0.01y +0.05y = 11.22

-0.01y+0.05y = 11.22-4.74

0.04y = 6.48

y= 6.48/0.04

y= 162

Replace y on (a) ans solve for x

x+y= 474

x + 162 = 474

x = 474 -162

x = 312

312 pennies

162 nickels