Distance

This topic has expert replies
Senior | Next Rank: 100 Posts
Posts: 61
Joined: Fri Jun 06, 2008 5:58 am
Thanked: 1 times

Distance

by moonlite » Wed Apr 22, 2009 3:33 pm
Aaron will jog from home at x miles per hour and then walk back home by the same route at y miles per hour. How many miles from home can Aaron job so that he spends a total of t hours jogging and walking?

a) xt/y
b) x+t/xy
c) xyt/x+y
d) x+y+t/xy
e) y+t/x - t/y

OA C
Can someone please explain how to solve this picking numbers?
I tried to pick 5 for x and 10 for y but i couldn't come up with the right answer, not sure what i'm doing wrong.

Thanks!!

Newbie | Next Rank: 10 Posts
Posts: 1
Joined: Wed Apr 22, 2009 4:47 pm

Re: Distance

by maverick009 » Wed Apr 22, 2009 5:03 pm
moonlite wrote:Aaron will jog from home at x miles per hour and then walk back home by the same route at y miles per hour. How many miles from home can Aaron job so that he spends a total of t hours jogging and walking?

a) xt/y
b) x+t/xy
c) xyt/x+y
d) x+y+t/xy
e) y+t/x - t/y

OA C
Can someone please explain how to solve this picking numbers?
I tried to pick 5 for x and 10 for y but i couldn't come up with the right answer, not sure what i'm doing wrong.

Thanks!!
Let the total distance he walks or jogs be d.
jog speed = x mph, walk speed = y mph
Time for jog = d/x, time for walk = d/y
Now, t = d/x + d/y
Find out d.
d = (xyt)/(x+y)