1.  Which one of the following is not a prime number?  
Answer: Option D Explanation: 91 is divisible by 7. So, it is not a prime number. 
4.  What least number must be added to 1056, so that the sum is completely divisible by 23 ?  

5.  1397 x 1397 = ?  
Answer: Option A Explanation:

6.  How many of the following numbers are divisible by 132 ? 264, 396, 462, 792, 968, 2178, 5184, 6336 

Answer: Option A Explanation:
132 = 4 x 3 x 11 So, if the number divisible by all the three number 4, 3 and 11, then the number is divisible by 132 also. 264 11,3,4 (/) 396 11,3,4 (/) 462 11,3 (X) 792 11,3,4 (/) 968 11,4 (X) 2178 11,3 (X) 5184 3,4 (X) 6336 11,3,4 (/) Therefore the following numbers are divisible by 132 : 264, 396, 792 and 6336. Required number of number = 4. 
7.  (935421 x 625) = ?  
Answer: Option B Explanation:
= 584638125 
8.  The largest 4 digit number exactly divisible by 88 is:  
Answer: Option A Explanation:
Largest 4digit number = 9999 88) 9999 (113 88  1199 88  319 264  55  Required number = (9999  55) = 9944. 
9.  Which of the following is a prime number ?  
Answer: Option D Explanation: Clearly, 97 is a prime number. 
10.  What is the unit digit in {(6374)^{1793} x (625)^{317} x (341^{491})}?  
Answer: Option A Explanation:
Unit digit in (6374)^{1793} = Unit digit in (4)^{1793} = Unit digit in [(4^{2})^{896} x 4] = Unit digit in (6 x 4) = 4 Unit digit in (625)^{317} = Unit digit in (5)^{317} = 5 Unit digit in (341)^{491} = Unit digit in (1)^{491} = 1 Required digit = Unit digit in (4 x 5 x 1) = 0. 