Question

On Friday, Kaitlyn went to the park to work out. She started with a slow jog at a constant rate for five minutes. She then increased her speed to a faster, constant pace for seven minutes. She took a three-minute break, then ran for another 7.5 minutes at a constant pace to finish her 2-mile run. She rested for the remainder of the time.

During what domain interval will she reach 1.5 miles?

22.5 ≤ s ≤ 25
12 ≤ 2 ≤ 15
15 ≤ 2 ≤ 22.5
5 ≤ s ≤ 12

Answer 1

Total running times: 5 min (slow) + 7 min (faster) = 12 min, then 3 min break → final run starts at 15 min and lasts 7.5 min, ending at 22.5 min. She finishes the 2 miles at 22.5 min, so the 1.5-mile point (between 0 and 2) must occur during the final running segment. Thus 15 ≤ s ≤ 22.5.