krutikaaaa wrote:
can someone explain this question
https://gmatclub.com/forum/edwin-is-pla ... 86309.htmlcan’t we just say total time T = 1500/ speed (edwin). splitting the time equally between two people = 1/2 * T which is 1/2*1500/speed(edwin). So the percentage reduction is 50% ? hence both statements are sufficient?
That's great that you're trying to think of this conceptually. Unfortunately, you need to think deeper; go into more details.
If the time is split, it just means that both people are going to spend equal amount of time driving. However, the total amount of time spent will not be reduced by 50%. It may even increase!
Consider if the George drove at the same rate as Edwin. Then they would get to Boston in the same exact time as before. The amount of time spent traveling would be exactly the same, no? Edwin would still be in the car with George.
Now, if the George happens to drive faster during his half of the drive, then the total traveling time would be reduced.
I think with these rate questions, it's best to write out the formula.
r (rate) x t (time) = d (distance).
If you apply the info given in the question, you get:
r(edwin) x t(edwin) = d
r(edwin) x t(half of together) + + r(george) x t(half of together) = d
(On the real test, abbreviate with letters such as "e" and "g" because it's much easier on your brain.)
Hopefully, writing out the equations this way, you can see that t(edwin) will be different than t(together). You don't know what the ratio is unless you are given certain info.
My AssessmentGiven your answer, it suggests that you need to take more time when confronted with questions/info. This will improve your critical thinking skills not only on the GMAT but also in life in general.
For example, answer this question. If you have a baseball and bat that costs together $1.10. The bat is $1 more than the baseball. How much is the baseball?