Peter's best time in swimming. Wrong soln from Kaplan?

This topic has expert replies
Newbie | Next Rank: 10 Posts
Posts: 4
Joined: Wed Mar 25, 2009 2:03 pm
Ladies and gentelmen, this is a Kaplan question. I suspect the the solution is wrong. Do you agree?

Before Race R, Peter's best time in swimming was 21 minutes. Did Peter beat this time in Race R ?

(1) Peter took between 0.3 and 0.4 hours to swim 1,500 meters in Race R.
(2) Peter took between 1,200 and 1,300 seconds to swim 1,500 meters in Race R.

Kaplan Solution:

The question asks whether P (Peter's most recent time) is anything less (i.e., faster) than 21 minutes. Statements (1) and (2) give bounded ranges of possible values for P. Some computation will be necessary to see ifthe statements can be used to show definitely whether P " 21. Your calculations will involve conversions, because the statements are
made in terms of hours and seconds, while the question stem uses minutes.

Statement (1) tells you that (0.3 x 60) < p < (0.4 x 60). P is therefore between 18 and 24 minutes - but that doesn't tell you if it was
less than 21 minutes. To change seconds to minutes, divide by 60, so Statement (2) becomes 1200/60 < p < 1300/60, or 20 < P < 21 2/3. Neither statement alone tells you if p < 21, nor can you get any farther by putting the two statements together.

Well, the problem with the solution ... the record is 21 minutes for how many miles?!

d
Source: — Data Sufficiency |

Legendary Member
Posts: 2467
Joined: Thu Aug 28, 2008 6:14 pm
Thanked: 331 times
Followed by:11 members

by cramya » Thu Mar 26, 2009 5:11 pm
imo Its a clear E.

The problem could have said for 1500 miles the time is 21 minutes.

What is that u dont agree with the solution? Could u pl help me understand better?


Regards,
CR

Newbie | Next Rank: 10 Posts
Posts: 4
Joined: Wed Mar 25, 2009 2:03 pm

by dacii » Thu Mar 26, 2009 5:17 pm
cramya thanks for your reply.

If it is 21 mins for 1500 miles the solution is good.
If it is 21 mins for 1 mile the solution is A.
If it is 21 mins for 5000 miles the solution is A.

The problem never states that it is 21 mins for 1500 miles. And we are supposed to never assume. So the solution is E because you don't know how many miles was the record race.

Am I missing something?

(PS what is imo?)

Legendary Member
Posts: 2467
Joined: Thu Aug 28, 2008 6:14 pm
Thanked: 331 times
Followed by:11 members

by cramya » Thu Mar 26, 2009 5:59 pm
IMO->In my opinion

Agree 1500 could have been specified.

Regards,
CR