Question

Heather is a cashier. She can ring up 12 customers in 9 minutes. At this rate, how many minutes does it take her to ring up 4 customers?

Answer 1

First of all, let's compare the statements. That will be;
12 customers=9 minutes
4 customers= Y minutes.
I represented the unknown with Y. Next, you need to cross multiply. 4 will multiply 9 to give 36 and 12 will multiply Y to give 12Y. That will be;
12Y=36
Divide both sides by 12
Y=36/12
Y=3
It takes 3 minutes to ring up 4 customers. Hope that helped. Have a nice day

Answer 2

9 minutes / 12 customers = 0.75 minutes per customer

4 customers x 0.75 minutes per customer = 3 minutes total for 4 customers