Question

Easy Medal


A group of friends is addressing wedding invitations. Casey can address 20 envelopes in one hour, Anne can address 47 envelopes in two hours, and Paula can address 70 envelopes in three hours. About how long will it take them to address 420 envelopes?

6.92 hours
22.83 hours
18.39 hours
6.28 hours

Answer 1

Casey -> 20 per hour
Anne -> 40/2 = 23.5 per hour
Paula -> 70/3 = 23.3... per hour
20 + 23.5 + 23.3 = 66.8333
420 / 66.8333 =

Answer 2

D 6.28 hours

Answer 3

yep