* Data Sufficiency question

[kohligulneet]

Bill and Sally see each other across a field. They are 500 feet apart. If at the same instant of time they start running toward each other in a direct line how far will Bill have traveled when they meet?

(1) Bill ran at an average speed that was 50% greater than Sally ’ s average speed.

(2) Bill ran at an average speed 4 feet per second faster than Sally ’ s average speed.

A detailed explanation will be appreciated.

Thanks!

[arnabgangully]

I tried to solve it with pen/paper .

However later i thought it would be better to solve it verbally.:)

We cannot calculate the distance if there is not information about the actual speeds of the BILL and SALLY,the same logic applies to both the option A and B so only option left is E or C If we use both the information we get the Individual speeds and then we can calculate the Distance Bill travelled before they Meet.

So ANswer has to be C.

[RonPurewal]

hi,
is this problem actually from the official GMAT PREP software? this folder is exclusively for problems from that software.

* if the problem is from GMATPREP, please post a screenshot as proof (either embedded in your post or posted at an image-hosting site such as postimage.org).

* if not, we'll have to delete the thread. in that case, please read the forum rules first... and then re-post the question in the correct folder, with a citation of the original source.

thanks.

[geezer0305]

Bill and Sally see each other across a field. They are 500 feet apart. If at the same instant of time they start running toward each other in a direct line how far will Bill have traveled when they meet?

(1) Bill ran at an average speed that was 50% greater than Sally ’ s average speed.

(2) Bill ran at an average speed 4 feet per second faster than Sally ’ s average speed.

A detailed explanation will be appreciated.

Thanks!

Hi,

The distance is 500 meters
Let Sally's speed be: Vs
Let Bill's speed be: Vb

Let the distance travelled by Bill when both meet = x mts
Thus, distance traveled by Sally = 500-x mts
Now, when they meet, both would have been running for the same time,

Time taken by Bill = X/Vb
Time taken by Sally = (500-x)/Vs

So, x/Vb = (500-x)/Vs-------eqn 1

Statement 1: Vb = Vs (1+50/100)
=> Vb = (3/2) *Vs
use the above relationship in eqn 1

=>2x/3Vs = (500-x)/Vs
=> 2x/3 = 500-x
Solve for x.

Statement 1 is sufficient



Statement 2: Vb= Vs + 4--->gives us the following equation:
when we replace Vb with Vs+4

2x/(Vs+4) = (500-x)/Vs

We have two variables and 1 equation-- we cannot solve further.
Therefore , STat 2 is insufficient.


Hope this helps.

Regards

[tim]

we still need a screenshot before we can discuss this problem..