Various latest topics from GMAT Club Forum

What is the remainder when \(2^k\) is divided by 10?

1) k is a positive multiple of 10
2) k is a positive multiple of 4

\(4^-^4/16^-^3=?\)

A. 4 B. 1/4 C. 8 D. 1/8 E. 16

Factory X and factory Y are among the 5 factories in a certain manufacturing business. If the CEO of a business must visit the 5 factories every day, in how many different possible orders can the CEO go to the factories so that factory X is ahead of factory Y?

A. 24
B. 30
C. 36
D. 48
E. 60

If a, b are integers, and (a-b)^2 + 8b^2=108, what is the number of the ordered pairs (a,b)?

A. 2
B. 4
C. 6
D. 8
E. 10

If ab - 2b = (4 - a)b, what is the value of b?

(1) |a^2 - 9| 0
(2) a < 0

If a, b are integers, and (a-b)^2 + 8b^2=108, what is the number of the ordered pairs (a,b)?

A. 2
B. 4
C. 6
D. 8
E. 10

Hi, I am looking for some clarity on when we CAN and CANNOT divide by a variable. :?:

Scenario 1:
x^2 = 10x
x^2/x = 10x/x would be incorrect.

We would need to solve this as follows:
x^2 - 10x = 0
x(x - 10) = 0
x=0 or x=10

Scenario 2:
y = 4x
y/x = 4x/x
y/x = 4

Why is it that we cannot divide by x in scenario 1, but we can divide by x in scenario 2?

Thank you for your help.

If x,y,z are positive integers,is the product x*y*z divisibly by 21?
(1) The greatest common factor of x, y, and z is 3.
(2) The lowest common multiple of x, y, and z is 63.

Source->Self-Made

Is |x+y|=|x|+|y|?

1) xy>0
2) x<0

There is a sequence an for a positive integer such that a3=a1+a2, a4=a3+a2+a1, an =an-1+an-2+an-3+.+a2+a1. If an=p, an+2=?

A. 2p B. 4p C. 8p D. 16p E. 24p

If a positive integer \(n\) is given by \(n=26*p\) where \(p\) is a prime number greater than 2,how many even divisors does n have ?

A)4
B)3
C)2
D)1
E)cannot be determined.

Source-> Self-Made

This topic have been merged with: http://gmatclub.com/forum/topic-130774.html

(1) s is the right of zero
(2) the distance between t and r is the same as the distance between t and -s.

Do we know that the points are in the order shown in the figure ? (or can they be in a different order ?) Do we know that they are distinct ?

Many thanks :-D

If \(N\) is a positive integer,what is the value of \(N\)?
(1) \(N\) is divisible by 31.
(2) \(\frac{N}{100}\) is a prime number.

Source->Self-Made

If b is a positive integer, then b has how many distinct positive factors?

(1) all of b's factors are also factors of 62.
(2) b is the product of one even prime number and one odd prime number.

If n is positive, is n an integer?

(1) 3n is an integer
(2) n < n^2

How many factors does y have?

(1) y is the cube of an integer.
(2) y is the product of 2 distinct positive digits.

Given that a and b are positive, is the ratio a:b greater than 5?

(1) a is 3 more than 5 times b

(2) The ratio of 4a to 5b is greater than 4

A number is said to be prime saturated if the product of all the different positive prime factors of n is less than the square root of n.
If p is a prime saturated,what is the value of p?

A)p is a perfect cube.
B)2p15

Source-> Self-Made

What is the remainder when 2^k is divided by 10?

4^-4/16^-3=?

Combinations-PS

If a, b are integers, and (a-b)^2 + 8b^2=108, what is the number of th

If ab - 2b = (4 - a)b, what is the value of b?

Factory X and factory Y are among the 5 factories in a certain manufac

If a, b are integers, and (a-b)^2 + 8b^2=108, what is the number of th

Division Rules

If x,y,z are positive integers,is the product xyz divisibly by 21?

Is |x+y|=|x|+|y|?

There is a sequence an for a positive integer such that a3=a1+a2, a4=

If a positive integer n is given by n=26p where p is a prime number

DS

On the number line shown, is zero halfway between r and s ?

If N is a positive integer, what is the value of N?

If b is a positive integer, then b has how many distinct positive fact

If n is positive, is n an integer?

How many factors does y have?

Given that a and b are positive, is the ratio a:b greater than 5

A number is said to be prime saturated if the product of all the diffe