gaurav05nov wrote:

Rodrick mixes a martini that has a volume of 'n' ounces having 40% Vermouth and 60% Gin by volume. He wants to change it so that the martini is 25% Vermouth by volume. How many ounces of Gin must he add?

A) n/6

B) n/3

C) 3n/5

D) 5n/6

E) 8n/5

I solved it like this,

Give n = 40% Vermouth + 60% Gin

I assume n=10, So, 10=4(Vermouth) + 6(Gin)

What we need is to add gin(Not Vermouth) to make

Vermouth 25% of solution..

4/10+x =1/4 , Here X is the ounce we are adding to make Vermouth 25% of solution.

X=6. Substitue n=10 in answer choices and watch for '6' as the answer-----> C

It looks little long when u jot it down step by step, but it solves almost all the Mixture and allegation Question with out any doubt.

_________________

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Shravan

GMATPrep--430, Q30,V20

++ 150Hrs ++

VeritasPrep--610, Q45,V29