Two friends are racing three miles. The first one runs it in 21 minutes. The second one runs it in 24 minutes. If they keep up the same pace, how long combined will it take for them to run 5 miles each?
Thoughts? Step-by-step reasoning:
The first one runs a mile in 7 minutes because 21 / 3 = 7. The second runs a mile in 8 minutes because 24 / 3 = 8. The first one would finish 5 miles in 35 minutes because 5 x 7 = 35. The second one would finish in 40 minutes because 5 x 8 = 40. It will take 75 minutes in total because 35 + 40 = 75.
Thus, the answer is 75.