Right and Wrong Permutations and Combinations Methods And Pointers That Will Make You Ace These On Your CSET Exam

1. There are 20 people who work in an office together. Four of these people are selected to go to the same conference together. How many such selections are possible?

A. 4,845

B. 5,800

C. 116,280

D. None of the above.

2. There are 20 people who work in an office together. Four of these people are selected to attend four different conferences. The first person selected will go to a conference in California, the second will go to Texas, the third to Chicago, and the fourth to New York. How many such selections are possible?

A. 4,845

B. 80

C. 116,280

D. None of the above.

3. Serial numbers are to be made using three letters (using any letter of the alphabet) followed by two single-digit numbers. For example, ZBY14 is one such serial number. How many such serial numbers are possible if neither letters nor numbers can be repeated?

A. 1,404,000

B. 117,000

C. 15,690

D. None of the above