BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Average Speed

Expert replies
by sparkle6 » Sun Sep 25, 2011 6:15 am
On a recent trip, Mary drove 50 miles. What was the average speed at which she drove the 50 miles?

1) She drove 30 miles at an average speed of 60 miles per hour and then drove the remaining 20 miles at an average speed of 50 miles per hour

2) She drove a total of 54 minutes

[spoiler]Answer: A, but I got D. [/spoiler]
Join the discussion
Source: — Data Sufficiency |

by cans » Sun Sep 25, 2011 8:06 am
IMO D
If my post helped you- let me know by pushing the thanks button ;)

Contact me about long distance tutoring!
[email protected]

Cans!!
Join the discussion

by rohit_gmat » Sun Sep 25, 2011 8:18 am
sparkle6 wrote:On a recent trip, Mary drove 50 miles. What was the average speed at which she drove the 50 miles?

1) She drove 30 miles at an average speed of 60 miles per hour and then drove the remaining 20 miles at an average speed of 50 miles per hour

2) She drove a total of 54 minutes

[spoiler]Answer: A, but I got D. [/spoiler]
u sure the OA is A???????
I think the answer is clearly D.. unless theres some crucial info tht has been missed out in the Q u put up here...
wats the source?[/spoiler]
Join the discussion

by sparkle6 » Sun Sep 25, 2011 10:06 pm
I got it from a series of worksheets that a friend passed on to me. It has had some mistakes in the past, so I'm guessing this answer also had a mistake.
Join the discussion

by chetansharma » Mon Sep 26, 2011 8:25 am
Clearly the answer is D. I think probably the answer is wrong

Regards,
Chetan
If my post helped you - let me know by pushing the thanks button :wink:
Join the discussion

by badpoem » Mon Sep 26, 2011 9:13 am
2) She drove a total of 54 minutes --> does not mention whether she drove with uniform speed or not. So, insufficient, IMO.
Join the discussion

by rohangupta83 » Mon Sep 26, 2011 3:06 pm
badpoem wrote:2) She drove a total of 54 minutes --> does not mention whether she drove with uniform speed or not. So, insufficient, IMO.
the question is asking for the average speed over the whole journey. It doesn't matter whether Mary drove at a constant speed or not.
Join the discussion

by GmatKiss » Mon Oct 03, 2011 12:55 pm
It has to be D
Join the discussion

by sl750 » Tue Oct 04, 2011 5:29 am
Answer is A.

Statement 2 is insufficient. We don't know whether she drove at a constant speed throughout the trip or not
Join the discussion