Answer: There are 75 Adults in the supermarket ask me why if you want a full on explanation. The full on reason of why it is 75 is because if you have a ratio of 1:5 and you now the one is for the kids and it is 15. Then you add 15 from 1 until you get to the 5th ratio. Hence, it brings you all the way to 75 adults. I hope this helped you, and anyone else