1. 

Which one of the following is not a prime number?

A. 31
B. 61
C. 71
D. 91

2. 

(112 x 54) = ?

A. 67000
B. 70000
C. 76500
D. 77200

3. 

It is being given that (232 + 1) is completely divisible by a whole number. Which of the following numbers is completely divisible by this number?

A. (216 + 1)
B. (216 - 1)
C. (7 x 223)
D. (296 + 1)

4. 

1397 x 1397 = ?

A. 1951609
B. 1981709
C. 18362619
D. 2031719

5. 

What least number must be added to 1056, so that the sum is completely divisible by 23 ?

A. 2
B. 3
C. 18
D. 21