Question

Kira's penny bank is

2/3full. After she removes
160 pennies, it is
4/9 full. How many pennies can Kira's bank hold?

Answer 1

2/3 = 6/9

so removing 160 pennies gets rid of 2/9 of the jar

which means 160 = 2/9 and 80 = 1/9

to find out the max amount you can multiply 9 x 80

and get 720.

Answer 2

compare
2/3 to 4/9

make denom the same
2/3 times 3/3=6/9

from 6/9, she removes 160 to get 4/9
6-4=2
therefor
6/9-2/9=4/9
also
2/9=160 coins
times 1/2
1/9=80 coins
times 9
1=720 coins

can hold 720 coins