Properties of numbers

1.which of following is a perfect number.

A.2                  B.28

C.12                D.19

2.How many prime numbers are exist between 50 and 100.

A.5                 B.8

C.10               D.15

3.Which of following is an even prime number.

A.2                B.4

C.5                D.3

4.Which of following is a composite number.

A.2              B.3

C.4              D.5

ans:-B,C,A,C.