Select the real world problem that could be solved using a proportion. Sheila travels 210 miles in 3 hours. At this rate how far will she travel in 7 hours?

Sheila has 3 dogs and adopts 2 more. How many dogs does she have in total?

Shiela must pay 210 for a phone and then 70 each month for service. How much will she have paid after 7 months?

Shiela has 3 pens and 7 pencils. How many more pens does she need to make the number of pens and pencils she has equivalent?