\( \Large 2^{16}-1 \) is divisible by


A) 11

B) 13

C) 17

D) 19

Correct Answer:
C) 17

Description for Correct answer:
\( \Large 2^{16}-1^{16} \)

\( \Large = (2^{8}-1^{8})(2^{8}+1^{8}) \)

\( \Large = (2^{4}-1)(2^{4}+1)(2^{8}+1) \)

\( \Large = (16-1)(16+1)(2^{8}+1) \)

\( \Large = 15 \times 17(2^{8}+1) \)

\( \therefore\Large 2^{16}-1 \) is divisible by 17

Part of solved Number series questions and answers : >> Aptitude >> Number series








Comments

No comments available




Similar Questions
1). Which one of the following will completely divide \( \Large 5^{71}+5\sqrt{72}+5^{73} \)?
A). 150
B). 160
C). 155
D). 30
-- View Answer
2). The least number, which is to be added to the greatest number of 4 digits so that the sum may be divisible by 345, is:
A). 50
B). 6
C). 60
D). 5
-- View Answer
3). Three numbers are in the ratio 1 : 2 : 3 and the sum of their cubes is 4500. The smallest numbers is.
A). 4
B). 5
C). 6
D). 10
-- View Answer
4). The sum of the numerator and denominator of a positive fraction is 11. If 2 is added to both numerator and denominator, the fraction is increased by \( \Large \frac{1}{24} \). The differ-ence of numerator and den-ominator of the fraction is:
A). 5
B). 3
C). 1
D). 9
-- View Answer
5). The denominator of a fraction is 3 more than its numerator. If the numerator is increased by 7 and the denominator is decreased by 2, we obtain 2. The sum of numerator and denominator of the fraction is
A). 5
B). 13
C). 17
D). 19
-- View Answer


6). A fraction becomes \( \Large \frac{1}{3} \) when 1 is subtracted from both the numerator and the denominator. The same fraction becomes \( \Large \frac{1}{2} \) when 1 is added to both the numerator and denominator. The sum of numerator and denominator of the fraction is:
A). 10
B). 18
C). 7
D). 16
-- View Answer
7). A girl was asked to multiply a number by \( \Large \frac{7}{8} \), instead she divided the number by \( \Large \frac{7}{8} \) and got the result 15 more than the . correc result. The sum of the digits of the number was:
A). 4
B). 8
C). 6
D). 11
-- View Answer
8). What least value must be assigned to '*' so that the numbers 451*603 is exactly divisible by 9?
A). 7
B). 8
C). 5
D). 9
-- View Answer
9). If 1 is added to both the numerator and the deno-minator of a fraction, it becomes \( \Large \frac{1}{4} \). If 2 is added to both the numerator and the denominator of that fraction it becomes \( \Large \frac{1}{3} \). The sum of the numerator and the denominator of the fraction is:
A). 8
B). 13
C). 22
D). 27
-- View Answer
10). A number whose one-fifth part increased by 4 is equal to its one-fourth part diminshed by 10 is:
A). 260
B). 280
C). 240
D). 270
-- View Answer