BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

pair (x, y) is not possible?

Expert replies
by sanju09 » Wed May 02, 2012 4:19 am
When positive integer n is divided by 5, the remainder is x. When 2n is divided by 5, the remainder is y. Which pair (x, y) is not possible?
(A) (2, 4)
(B) (0, 0)
(C) (4, 3)
(D) (3, 1)
(E) (3, 2)



https://www.crushthetest.com
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Join the discussion
Source: — Problem Solving |

by gschaefer » Wed May 02, 2012 12:38 pm
In order to solve this problem, I tested 5 consecutive number to see which pair is not possible.

r= remainder

n=6 -> r=1
2n = 12 -> r= 2
Pair (1,2) not mentioned as solution

n=7 -> r=2
2n=14 -> r=4
A is possible

n=8 -> r=3
2n=16 -> r=1
D is possible

n=9 -> r=4
2n=18 -> r=3
C is passible

n=10 -> r=0
2n=20 ->r=0
B is possible

Hence pair E is not possible.
Join the discussion