1. 
Which one of the following is a prime number ?
 
Answer: Option C
Explanation:
437 > 22
All prime numbers less than 22 are : 2, 3, 5, 7, 11, 13, 17, 19.
161 is divisible by 7, and 221 is divisible by 13.
373 is not divisible by any of the above prime numbers.
373 is prime.

2. 
The smallest 6 digit number exactly divisible by 111 is:
 
Answer: Option C
Explanation:

3. 
The largest 5 digit number exactly divisible by 91 is:
 
Answer: Option B
Explanation:

4. 
 
Answer: Option A
Explanation:

5. 
The smallest 5 digit number exactly divisible by 41 is:
 
Answer: Option B
Explanation:

6. 
How many terms are there in the G.P. 3, 6, 12, 24, ... , 384 ?
 
Answer: Option A
Explanation:
Then, t_{n} = 384 ar^{n1} = 384
3 x 2^{n  1} = 384
2^{n1} = 128 = 2^{7}
n  1 = 7
n = 8
Number of terms = 8.

7. 
If x and y are positive integers such that (3x + 7y) is a multiple of 11, then which of the following will be divisible by 11 ?
 
Answer: Option D
Explanation:
By hit and trial, we put x = 5 and y = 1 so that (3x + 7y) = (3 x 5 + 7 x 1) = 22, which is divisible by 11.
(4x + 6y) = ( 4 x 5 + 6 x 1) = 26, which is not divisible by 11;
(x + y + 4 ) = (5 + 1 + 4) = 10, which is not divisible by 11;
(9x + 4y) = (9 x 5 + 4 x 1) = 49, which is not divisible by 11;
(4x  9y) = (4 x 5  9 x 1) = 11, which is divisible by 11

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