Problem Solving

A is two years older than B who is twice as old as C. If the total of the ages of A, B and C be 27, the how old is B?

(A)10
(B)33
(C)7
(D)8
(E)11

pzazz12 wrote:A is two years older than B who is twice as old as C. If the total of the ages of A, B and C be 27, the how old is B?

(A)10
(B)33
(C)7
(D)8
(E)11

Is it A?

A=B+2
B=2C
A+B+C=27
B+2 + B + B/2 = 27
Solving for B , you will get B =10

There is another way to solve the question without using the equation.

Since B is twice old as C and age cannot be in fraction, therefore age of B will be always even number.

So you can easily eliminate choices (B) (C) and (E).

Now if you choose (A),

then B = 10, A = 12 and C = 5
Total = 27

Choose (A).

However, this method may not be applicable for all question but somehow it work for this question.

Enjoy!!!

A is two years older than B who is twice as old as C. If the total of the ages of A, B and C be 27, the how old is B?

It gives a simple equation i.e.

A+B+C = 27

=> B+2+B+B/2 = 27
=> 5B = 50
=> B = 10

Hence the answer is (A)

Hey guys,

These age problems are great examples of a thought process that I think is extremely helpful on this test for any word problems:

The word "IS" (or any form of the verb "to be") means "equals" (=). So when converting word problems to equations, let that word IS be your guide:

A is two years older than B
A = 2 years older than B
A = 2 + B


B is twice as old as C
B = twice C
B = 2C

Now you have pure math to work with, and you're asked to solve for B (we also have the equation A + B + C = 27), so you' ll want to put all of the equations in terms of B:

A = 2 + B
C = B/2

So: (2 + B) + B + (B/2) = 27

2B + B/2 + 2 = 27
2B + B/2 = 25
(find a common denominator for the B terms: 4B/2 + B/2 = 5B/2)

5B/2 = 25
5B = 50
B = 10

When approaching word problems, keep in mind that they almost always give you the operations just in word form.

Is --> =
More than ---> +
Of ---> * (multiplication)
Per ---> divided by
Percent ---> /100

etc.

Get used to making these quick translations and you can make word problems pretty easy to set up.

msbinu wrote:

pzazz12 wrote:A is two years older than B who is twice as old as C. If the total of the ages of A, B and C be 27, the how old is B?

(A)10
(B)33
(C)7
(D)8
(E)11

We can just plug in the answers, which represent the age of B. Since B is twice as old as C and the sum of the ages is an integer (27), B's age must be even. Eliminate B, C and E.

Answer choice A:
B= 10
C = 5 (Since B is twice as old)
A = 12 (Since A is 2 years older than B)

A+B+C = 12+10+5 = 27. Success!

The correct answer is A.