Resident always seems to have a dirty truck his girlfriend gave him a gift card to car wash after three carwashes rest at 61.75 left on the card after six what is he at 23.50 left on the card how much money was on the gift card initially

I'm thinking it's $100. I guessed 100 first as that is a pretty common number and subtracted 61.75. I was left with 38.25 and I divided that by 3, the amount of washes. I got $12.75 but I had to check since I guessed 100. I then subtracted 23.50 from 100 and got 76.5. I divided that by 6, the amount of washes, and got 12.75 again. So I'm pretty sure that there was $100 on the gift card before he washes his car six times, each wash being $12.75.