Exercise :: Numbers  General Questions
 Numbers  Important Formulas
 Numbers  General Questions
91.  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. 
92.  The smallest 6 digit number exactly divisible by 111 is: 

Answer: Option C Explanation: The smallest 6digit number 100000. 111) 100000 (900 999  100  Required number = 100000 + (111  100) = 100011. 
93.  The largest 5 digit number exactly divisible by 91 is: 

Answer: Option B Explanation: Largest 5digit number = 99999 91) 99999 (1098 91  899 819  809 728  81  Required number = (99999  81) = 99918. 
94. 


Answer: Option A Explanation:

95.  The smallest 5 digit number exactly divisible by 41 is: 

Answer: Option B Explanation: The smallest 5digit number = 10000. 41) 10000 (243 82  180 164  160 123  37  Required number = 10000 + (41  37) = 10004. 
96.  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. 
97.  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. 
98.  9548 + 7314 = 8362 + (?) 

Answer: Option C Explanation: 9548 16862 = 8362 + x + 7314 x = 16862  8362  = 8500 16862  
99.  In a division sum, the remainder is 0. As student mistook the divisor by 12 instead of 21 and obtained 35 as quotient. What is the correct quotient ? 

Answer: Option D Explanation: Number = (12 x 35) Correct Quotient = 420 ÷ 21 = 20 
100.  2 + 2^{2} + 2^{3} + ... + 2^{9} = ? 

Answer: Option B Explanation:
