Kim started hiking at 10:40 AM. She stopped for lunch at 1:10 PM, having hiked an average rate of 3 miles per hour. How far did she hike?

So first find time elapsed

10:40-11:40=1

11:40-12:40=1

12:40-1:10=0.5 or 30 mins

so add

1+1+0.5=2.5, 2 hours 30 mins

3 miles per hour

3 times numberof ohours

3 times 2.5

7.5

answer is 7.5 miles