31.The number of different prime factors of 48

The number of different prime factors of 72

答案：C

32.The number of different positive divisors of 12

The number of different positive divisors of 50

答案：C

33.The number that is as much greater than 63 as it is less than 101

84

答案：B

34. A K-number is a positive integer with the special property that 3 times its units’ digit is equal to 2 times its tens’digit.

The number of K-numbers between 10 and 99

3

答案：C