1. X is a positive integer. 2-height of X is defined as the greatest negative integer n where 2^n is a factor of X. K and M are two positive integers. Whether 2-height of K is greater than 2-height of M? a. K is greater than M b. K is even times of M (Key: B)
2. X, Y and Z are three different prime numbers. How many factors does X*Y*Z have? (Key: 8)
3. XY>Z? a. XYZ>1 b. XYZ^2=1 (Key: C)
4. XYZ>0? a. XY>0 b. YZ>0 (Key: E)
5. 7^3*7^4=? (Key: 7^7)
6. A is 25% less than B and B is 25% less than C. How much percent is A less than C? (Key: 1/3)
7. A can finish one job in X hours. A does this job three times as fast as B does. If A and B work together, how many hours can they finish the job? (Key: 3X/4)