Bunuel
If Phil’s age is exactly half of Jan’s age, what is Jan’s age?
(1) In 24 years, Jan’s age will be 25% greater than Phil’s.
(2) 6 years ago, Phil’s age was 1/5 Jan’s age.
Let P = Phil's PRESENT age
Let J = Jan's PRESENT age Given: Phil’s age is exactly half of Jan’s age We can write:
P = 0.5J Target question: What is Jan’s (PRESENT) age? Statement 1: In 24 years, Jan’s age will be 25% greater than Phil’s. In 24 years...
J + 24 = Jan's age
P + 24 = Phil's age
So, we can write:
J + 24 = 1.25(P + 24) [a linear equation with two variables]We also have:
P = 0.5J [a different linear equation with the same two variables] Since we have a system of two linear equations with two variables, we COULD solve the system for P and J, which means we COULD answer the
target question with certainty.
So, statement 1 is SUFFICIENT
Statement 2: 6 years ago, Phil’s age was 1/5 Jan’s age.6 years ago,...
J - 6 = Jan's age
P - 6 = Phil's age
We can write:
J - 6 = (1/5)(P - 6) [a linear equation with two variables]We also have:
P = 0.5J [a different linear equation with the same two variables] Since we have a system of two linear equations with two variables, we COULD solve the system for P and J (although we would never waste precious time on test day actually solving the system), which means we COULD answer the
target question with certainty.
So, statement 2 is SUFFICIENT
Answer: D
Cheers,
Brent