How would you solve this question:

A balloon at 1.00 ft altitude (from sea level) has an internal pressure of 865 torr. The balloon is released into the atmosphere and it rises to 15,000 ft. What is the pressure in torr at this altitude if the volume of the gas increased 25 times?

I used P1V1=P2V2 and answered 34.6 but it marked me wrong and said answer was 34.8

Your answer is right
so you will get the credit of this question
well done Vineeth!