GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 22 Apr 2019, 07:15

### GMAT Club Daily Prep

#### 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

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

# Two musicians, Maria and Perry, work at independent constant

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Aug 2009
Posts: 7575
Re: Two musicians, Maria and Perry, work at independent constant  [#permalink]

### Show Tags

10 Apr 2018, 21:58
1
Bunuel chetan2u

Quote:
Two musicians, Maria and Perry, work at independent constant rates to tune a warehouse full of instruments. If both musicians start at the same time and work at their normal rates, they will complete the job in 45 minutes. However, if Perry were to work at twice Maria’s rate, they would take only 20 minutes. How long would it take Perry, working alone at his normal rate, to tune the warehouse full of instruments?

A. 1 hr 20 min
B. 1 hr 45 min
C. 2 hr
D. 2 hr 20 min
E. 3 hr

Let the whole work be 180 units.

Is the highlighted text LCM of 45 and 20? If so, are not these mentioned as time units in main question stem?
How can I use smart numbers for two different variables wiz units and time?

Hi...

It is taken as LCM of 45 and 20....
You have to just realize that what ever value you take, it will have t o be divided by 45 and 20..

otherwise..
M and P together do in 45 min..
Twice M + M or 3 Ms do in 20 min, so M will do in $$20*3= 60$$ min.

So if P joins M, it takes 45 min instead of 60 min..
But for 45 minutes M is also working, so work P does in 45 minutes saves 15 minutes of M work...
This means P takes $$\frac{45}{15}$$ times M's time, so $$60*3=180$$ min..
_________________
Manager
Joined: 03 Sep 2018
Posts: 61
Re: Two musicians, Maria and Perry, work at independent constant  [#permalink]

### Show Tags

13 Apr 2019, 02:18
Easiest way:

3r*1/3=1 -> t=1h=60min

1*3/4+3x/4=1 -> 3+3x=4-> x=1/3 –> t=3h

done.
_________________
Re: Two musicians, Maria and Perry, work at independent constant   [#permalink] 13 Apr 2019, 02:18

Go to page   Previous    1   2   [ 22 posts ]

Display posts from previous: Sort by