There are N questions in an exam.
For i= 1, 2,..... N ,
there are 2N-1 students who answered i or more questions wrongly. If total number of wrong answers is 8191, N then will be
A. | 12 |
B. | 11 |
C. | 10 |
D. | 13 |
Option: D Explanation :
Number of students who answered 1 or more questions wrongly = 2^{N-1}. Click on Discuss to view users comments. |
In an election for the President, if 261 valid votes are cast, for the 5 contestants then least number of votes a candidate requires to receive to win the election are
A. | 53 |
B. | 54 |
C. | 257 |
D. | 72 |
Option: A Explanation :
Worst scenario is when other four get equal number of votes. Click on Discuss to view users comments. |
If 7x + 6y = 420, x and y are natural numbers, then what can be said about x?
A. | x is always odd |
B. | x is always even. |
C. | x is even only if y is odd. |
D. | x is odd if y is even. |
Option: B Explanation :
7x + 6y = 420 Click on Discuss to view users comments. |
Which of the following is/are true?
I. When Arithmetic Mean of a set of values and number of values in the set are known, then Geometric Mean of the set can be found out.
II. When Arithmetic Mean of a set of values and number of values in the set are known, sum of all the elements in the set can be found out.
III. When Geometric Mean of a set of values and number of values in the set are known, then Arithmetic Mean of the set can be found out.
Codes :
A. | Only I |
B. | Only. II |
C. | Only I and II |
D. | All except II |
Option: B Explanation :
Consider a set of three numbers a, b and c. Thus, a + b + c = 3AM. which cannot be found out. Thus, I is false, Sum of the numbers = a + b + c = 3AM. Thus, II is true. which cannot be found out. Thus, III is false. Click on Discuss to view users comments. |
Two new charity organizations C_{1} and C_{2} were formed, with x members each, on January 1, 2012. On first day of each, subsequent month, in C_{1}, number of members increases by a certain number a, while in C_{2}, number of members increases in such a way that ratio of the number of members in a month to the preceding month bear a ratio equal to b. On May 1, 2012, both organizations had the same number of members. If a = 20x, then b will be
A. | 2 |
B. | 3 |
C. | 2.5 |
D. | 3.5 |
Option: B Explanation :
Number of members in C_{1} on May 1, 2012 = x + 4ya Click on Discuss to view users comments. |