Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized for You

we will pick new questions that match your level based on your Timer History

Track Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

On his trip to Alaska, Joe traveled y percent of the total [#permalink]

Show Tags

31 Oct 2012, 11:46

Expert's post

9

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

45% (medium)

Question Stats:

70% (03:24) correct
30% (03:10) wrong based on 149 sessions

HideShow timer Statictics

On his trip to Alaska, Joe traveled y percent of the total distance at an average speed of 50 miles per hour and the rest of the distance at an average speed of 70 miles per hour. What was Joe’s average speed in miles per hour for the whole trip in terms of y?

(A) 70(50 – y)

(B) (y + 60)/4

(C) 10,000 – 199y

(D) 17,500/(y + 250)

(E) y/2 + 35

If the first part is at 50 mile/h and the second part is 70 miles/h the overall speed is the toral distance / total time.

Pick a number for distance we can use 350. so the time for first part is 7 and for the rest is 5.

in the end we will have 26. something, but testing answer choices nothing comes up (

where I'm wrong

PS: I could use a bit of logic and come to the answer easier, but .............

Re: On his trip to Alaska, Joe traveled y percent of the total [#permalink]

Show Tags

01 Nov 2012, 06:27

3

This post received KUDOS

Expert's post

5

This post was BOOKMARKED

carcass wrote:

On his trip to Alaska, Joe traveled y percent of the total distance at an average speed of 50 miles per hour and the rest of the distance at an average speed of 70 miles per hour. What was Joe’s average speed in miles per hour for the whole trip in terms of y?

(A) 70(50 – y)

(B) (y + 60)/4

(C) 10,000 – 199y

(D) 17,500/(y + 250)

(E) y/2 + 35

If the first part is at 50 mile/h and the second part is 70 miles/h the overall speed is the toral distance / total time.

Pick a number for distance we can use 350. so the time for first part is 7 and for the rest is 5.

in the end we will have 26. something, but testing answer choices nothing comes up (

where I'm wrong

PS: I could use a bit of logic and come to the answer easier, but .............

Say y=100%, so say Joe traveled entire trip at an average speed of 50 miles per hour. So, in this case we'd have that his average speed is simply 50 miles per hour.

Now, plug y=100 into the answer choices and see which one yields 50. Only answer choice D fits.

Or: say y=0%. In this case we'd have that Joe's average speed is 70 miles per hour.

Now, plug y=0 into the answer choices and see which one yields 70. Again, only answer choice D fits.

Re: On his trip to Alaska, Joe traveled y percent of the total [#permalink]

Show Tags

06 Nov 2012, 09:01

BangOn wrote:

As you need a quick logical answer let me try Lety distance be X so Time 1 = XY/100*50 Time 2 = X(100-Y)/100*70

Avg Speed = Total Distance / Total Time = X/ Time 1 + Time 2

Ans D reason is simple...X cancels and Y reamins in denominator only 1 option has the same

I deducted the above within 30 secs but took another 3 mins to solve the whole mess to get to the ans choice. As you rightly said if we notice Y remains in deno for only one choice, life becomes easier.

I tend to go the conventional way every time not the GMAT way

Any other tricks like this which could help save TIME?

Re: On his trip to Alaska, Joe traveled y percent of the total [#permalink]

Show Tags

06 Nov 2012, 09:10

Another way - less than 2 mins Take Total distance = 100 1) y% of 100 at 50 mi/hr = distance is y miles -- So its y miles at 50 mi/hr 2) remaining (100-y) miles at 70 mi/hr

Avg spd = Total Dist/Total Time = 100/(y/50 + (100-y)/70) -> leads to D.(in case there are more choices with y in deno)

Re: On his trip to Alaska, Joe traveled y percent of the total [#permalink]

Show Tags

06 Nov 2012, 09:38

Expert's post

HiteshPunjabi wrote:

Another way - less than 2 mins Take Total distance = 100 1) y% of 100 at 50 mi/hr = distance is y miles -- So its y miles at 50 mi/hr 2) remaining (100-y) miles at 70 mi/hr

Avg spd = Total Dist/Total Time = 100/(y/50 + (100-y)/70) -> leads to D.(in case there are more choices with y in deno)

Re: On his trip to Alaska, Joe traveled y percent of the total [#permalink]

Show Tags

15 Nov 2012, 10:50

i just plugged in some random nos-

say Total distance=100 y=30% Then ball parked to find that D is the ans. _________________

I've failed over and over and over again in my life and that is why I succeed--Michael Jordan Kudos drives a person to better himself every single time. So Pls give it generously Wont give up till i hit a 700+

Re: On his trip to Alaska, Joe traveled y percent of the total [#permalink]

Show Tags

23 Aug 2014, 20:46

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email. _________________

Re: On his trip to Alaska, Joe traveled y percent of the total [#permalink]

Show Tags

02 Sep 2015, 10:27

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email. _________________

Post your Blog on GMATClub We would like to invite all applicants who are applying to BSchools this year and are documenting their application experiences on their blogs to...

HBS alum talks about effective altruism and founding and ultimately closing MBAs Across America at TED: Casey Gerald speaks at TED2016 – Dream, February 15-19, 2016, Vancouver Convention Center...