Help does this maths question make sense and what is the answer ? A man decides to use the stairs?

Question

...  instead of the elevator, he must  to walk up 19 flights of stairs to his level. If he runs up 5 of the 19 it takes 68.5 seconds, if he runs up 12 of the 19 flights it takes 58 seconds . How long will it take to walk the whole way?

Answer

Perhaps it means that when he runs 5/19, he walks the rest of the way and ditto for 12/19...?

Answer

1) 5r + 14w = 68.5s
2) 12r + 7w = 58s

In order to eliminate r multiply equation 1) by 12/5 = 2.4 ...

3):= 2.4 * 1) 12r + 33.6w = 164.4s

... and subtract 2) from 3)

4):=3)-2) 26.6w = 106.4s | :26.6
5) w = 4s

19 flights walking at 1flight/4s ?

19w * 4s = 76s.

Help does this maths question make sense and what is the answer ? A man decides to use the stairs?

Answers (2)