Algebra

Hi Roland2rule,

We're told that John is one year older than three times Linda's age, and the sum of their ages is 33 years. We're asked for John's age in 4 YEARS.

There are a couple of different ways to approach this question - since the answer choices are relatively small, you can actually use some 'brute force' arithmetic and get the correct answer without too much trouble:

IF...
Linda is 1, then John is 4 and the total is 5
Linda is 2, then John is 7 and the total is 9
Linda is 3, then John is 10 and the total is 13

Notice how the total age increases by 4 years each time... getting from a total of 13 years to a total of 33 years shouldn't be too tough (it's just 5 more 'steps'):
Linda is 8, then John is 25 and the total is 33

Thus, in 4 years, John will be 25+4 = 29

Final Answer: C

GMAT assassins aren't born, they're made,
Rich

BTGmoderatorRO wrote:John is one year older than three times Linda's age. If their ages currently add up to 33 years, then how old will John be in 4 years?
A. 12
B. 25
C. 29
D. 30
E. 37
OA is c
How can I go about getting the correct answer here? Thanks

We can let John’s current age = J and Linda’s current age = L and create the following equations:

J = 1 + 3L

and

J + L = 33

Thus:

1 + 3L + L = 33

4L = 32

L = 8, so J = 25. So, in 4 years, John will be 29.

Answer: C