Algebra 1 question help! I don't understand how to solve this question!!

Question

Mark charged a battery. Each minute, the percentage of the battery's capacity that was charged increased by 2.52 percent. After 17 minutes of charging, the battery was 61.5 percent full.

 

How full was the battery when the charging began?


How long from the time that Mark started charging did it take the battery to be fully charged?

Answer 1

2.52%*17=42.84%

61.5%-42.84%=18.66% full when the charging began

18.66%+2.52%*x=100% where x=# of minutes it takes to fully charge the battery

100%-18.66%=2.52%x

81.34%=2.52%x

x=81.34%/2.52%

x=32.2777... minutes or 32.3 minutes approximately