1. if m and n are positive integers, what is the remainder when 3 ^ (4n +2) + m is divided by 10?
A. n= 2
B. m =1
Please note it is only 3 to the power of (4n+2)
ANS - B
2. for which of the following functions is f(a+b) = f(a) + f(b) for all positive numbers a and b?
A. f(x) = x^2
B. f(x) = f(x+1)
C. f(x) = sqrt x
D. f(x) = x/2
E. f(x) = -3x
Ans: E
Thanks,
AJ
GMAT Prep software question
This topic has expert replies
- jayhawk2001
- Community Manager
- Posts: 789
- Joined: Sun Jan 28, 2007 3:51 pm
- Location: Silicon valley, California
- Thanked: 30 times
- Followed by:1 members
1 - insufficient. Without knowing m, we cannot find the remainderatarafder wrote:1. if m and n are positive integers, what is the remainder when 3 ^ (4n +2) + m is divided by 10?
A. n= 2
B. m =1
Please note it is only 3 to the power of (4n+2)
2 - sufficient.
3^(4n+2) + m
= 9^(2n+1) + m
We know that 9^(2n+1) will yield a number with units digit 9
So, knowing m, we can find the last digit of 3^(4n+2) + m
and hence the remainder when the above is divided by 10.
Hence B.
atarafder wrote: 2. for which of the following functions is f(a+b) = f(a) + f(b) for all positive numbers a and b?
A. f(x) = x^2
B. f(x) = f(x+1)
C. f(x) = sqrt x
D. f(x) = x/2
E. f(x) = -3x
Ans: E
Is the question copied correctly ?
Is B f(x) = f(x+1) or just x+1 ?
A - f(a) + f(b) = a^2 + b^2 which is not equal to (a+b)^2
B - please check
C - sqrt-a + sqrt-b not equal to sqrt (a+b)
D - seems to satisfy as well
E - seems to satisfy