It is currently 26 Jun 2019, 02:58

### 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

# Louise is three times as old as Mary. Mary is twice as old a

Author Message
TAGS:
GRE Prep Club Legend
Joined: 07 Jun 2014
Posts: 4809
GRE 1: Q167 V156
WE: Business Development (Energy and Utilities)
Followers: 120

Kudos [?]: 1910 [0], given: 397

Louise is three times as old as Mary. Mary is twice as old a [#permalink]  19 Aug 2018, 03:41
Expert's post
00:00

Question Stats:

68% (01:41) correct 31% (01:39) wrong based on 16 sessions
Louise is three times as old as Mary. Mary is twice as old as Natalie. If Louise is L years old, what is the average (arithmetic mean) age of the three women, in terms of L?

(A) $$\frac{L}{3}$$
(B) $$\frac{L}{2}$$
(C) $$\frac{2L}{3}$$
(D) $$\frac{L}{4}$$
(E) $$\frac{L}{6}$$
[Reveal] Spoiler: OA

_________________

Sandy
If you found this post useful, please let me know by pressing the Kudos Button

Try our free Online GRE Test

GRE Instructor
Joined: 10 Apr 2015
Posts: 2022
Followers: 62

Kudos [?]: 1841 [1] , given: 9

Re: Louise is three times as old as Mary. Mary is twice as old a [#permalink]  21 Aug 2018, 11:36
1
KUDOS
Expert's post
sandy wrote:
Louise is three times as old as Mary. Mary is twice as old as Natalie. If Louise is L years old, what is the average (arithmetic mean) age of the three women, in terms of L?

(A) $$\frac{L}{3}$$
(B) $$\frac{L}{2}$$
(C) $$\frac{2L}{3}$$
(D) $$\frac{L}{4}$$
(E) $$\frac{L}{6}$$

GIVEN: Louise is L years old

Louise is three times as old as Mary
This also means that Mary is 1/3 as old as Louise
Louise's age = L
So, Mary's age = (1/3)L = L/3

Mary is twice as old as Natalie.
This also means that Natalie is 1/2 as old as Mary
Mary's age = L/3
So, Natalie's age = (1/2)(L/3) = L/6

What is the average (arithmetic mean) age of the three women, in terms of L?
Average age = (sum of all 3 ages)/3

Sum of all 3 ages = L + L/3 + L/6
= 6L/6 + 2L/6 + L/6 [I rewrote each fraction with a common denominator of 6]
= 9L/6
= 3L/2

So, average age = (3L/2)/3
= L/2

Cheers,
Brent
_________________

Brent Hanneson – Creator of greenlighttestprep.com

Re: Louise is three times as old as Mary. Mary is twice as old a   [#permalink] 21 Aug 2018, 11:36
Display posts from previous: Sort by