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.comSign up for GRE Question of the Day emails