Carcass wrote:
In three years, Janice will be three times as old as her daughter. Six years ago, her age was her daughter’s age squared. How old is Janice?
A. 18
B. 36
C. 40
D. 42
E. 45
Kudos for the right answer and explanation
Question part of the project GRE Quantitative Reasoning Daily Challenge - (2021) EDITIONGRE - Math BookGIVEN:
SIX YEARS AGO, Janice's age was her daughter’s age squared. Take each answer choice (Janice's PRESENT age) and
subtract 6 years to see which one(s) yield(s) the square of an integer.
A. 18
- 6 =
12. Since
12 is NOT the square of an integer, ELIMINATE A
B. 36
- 6 =
30. Since
30 is NOT the square of an integer, ELIMINATE B
C. 40
- 6 =
34. Since
34 is NOT the square of an integer, ELIMINATE C
D. 42
- 6 =
36. Since
36 IS the square of an integer, KEEP D
E. 45
- 6 =
39. Since
39 is NOT the square of an integer, ELIMINATE E
Answer: D
ASIDE: It doesn't take long to confirm that D is, indeed, the correct answer.
Cheers,
Brent