Friday, April 3, 2009

Non- routine questions

Jeff took 8 hours to travel from Town A to Town B.
Nick took 12 hours to travel from Town B to Town A
Both Jeff and Nick started at 0930.
At what time would they pass each other on the way?

Actually, this is a relatively simple question... If you know how to do it, it is very easy.


The solution is below.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

METHOD 1:


Let the distance between Town A and Town B be 24km.

Speed of Jeff : Dist/Time = 24km/8h = 3km/h
Speed of Nick : Dist/Time = 24km/12h = 2km/h
Time taken to meet = Dist/Total speed
= 24/ 3+2
= 24/5
= 4.8h = 4h 48 min

0930 --4h 48 min ------ 1418--> ANSWER!

Simple???


METHOD 2 :

Jeff : 8h --> 1 journey
1h --> 1/8 journey

Nick : 12h --> 1 journey
1h --> 1/12 journey

1/8 + 1/12 = 3/24 + 2/24 = 5/24

5/24 journey = 1h
24/24 journey = 24/5 h = 4.8h = 4h 48min

1 comment:

  1. I think that all your maths posts are well done overall. The posts have both brief explaination and also questions and answers. This allows the readers to understand the topic easily.

    ReplyDelete