1. Five letters are to be selected from the word LOGARITHM. How many of these choices contain atleast 4 consonants?

a. 6
b. 45
c. 51
d. 126

2. Which of the following expressions is equivalent to C (n,r)?

a. n! / (n-r)! r!
b. n! / (n-r)!
c. (n-r)! r! /n!
d. (n-r)! / r!