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 MaryThis 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

= 6

L/6 + 2

L/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

Answer: B

Cheers,

Brent

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Brent Hanneson – Creator of greenlighttestprep.com

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