Mai's penny bank is 7/10 full. After she removes 200 pennies, it is 1/2 full. How many pennies can Mai's bank hold?

1/2 is equal to 5/10.

When Mai removes 200 pennies from her penny bank, the container drops from 7/10 full to 5/10 full.

7/10-5/10=2/10=1/5

200 pennies is 1/5 the capacity of the penny bank.

1/5 of the bank is 200 pennies, so a full bank is 1000 pennies.

Mai's penny bank can hold 498 pennies without being full.