Answer: 37.5 minutes
Explanation:
It takes Jahanna 50 minutes to deliver to 40 customers.
On Sunday however, she has to deliver to only 30 customers.
Assume that the amount of time it will take her is x minutes and use direct proportion:
50 minutes : 40 customers
x minutes : 30 customers
Cross multiply:
40x = 50 * 30
40x = 1,500
x = 1,500/40
x = 37.5 minutes