Speed time and distance

This topic has expert replies
User avatar
Senior | Next Rank: 100 Posts
Posts: 72
Joined: Tue Apr 19, 2011 6:58 am
Followed by:6 members

Speed time and distance

by jayanti » Fri Jul 15, 2011 11:05 am
ram covers a part of his journey at 20 mph and the balance at 70mph taking total of 8 hours to cover the distance of 400m. How may hours Ram has been driving at 20 mph...
Source: — Problem Solving |

Junior | Next Rank: 30 Posts
Posts: 13
Joined: Mon May 09, 2011 10:19 am
Thanked: 3 times
GMAT Score:720

by sandeeptalla450 » Fri Jul 15, 2011 11:11 am
Assume, time for which Ram travels at 20mph is 'x'. Since, total time taken is 8 hours, he travels the remaining time i.e. (8-x) hours at 70mph. So, we get the equation:

400 = 20*x + (8-x)*70

x=3.2 hours