1. What is the greatest common divisor of positive integers m and n?C
1) m is a prime number
2) m and n are consecutive integers
Unless n is a multiple of m, there is no common divisor except 1. INSUFF
Unless m and n are 1 and 2, there are no common divisors. INSUFF
Together, if m is prime and n is the next integer, there can be no common divisors. (I assume that m and n are in that order, because I believe that is what statement 2 means. If I cannot assume that, then it is E.)
2. Is number A more close to 10^(-2) or 10^(-3)? E
(1) A is more close to 10^(-1) than to 10(-4)
(2) A is more close to 10^(-2) than to 10(-4)
Q: Is A less than average of 1/100 and 1/1000?
A< 9/2000 ?
A is less than average of 1/10 and 1/10000.
A is less than average of 1/100 and 1/10000
A< 9.9/2000 INSUFF
Together still INSUFF.
3. How many different prime factors does N have?
(1) 2N has 4 different prime factors.
(2) N ^2 has 4 different prime factors.
2 may or may not be a factor of N as well. INSUFF
Prime factors should be the same for both N and N^2. SUFF