View in English View in Hindi 
Find the sum of the given series: 3 + 9 + 27 + 81 + 243 + 729 + 2187 + 6561 
A) 9840
B) 9855
C) 7960
D) 8892
Correct Answer : 9840 Explanation : 3 + 9 + 27 + 81 + 243 + 729 + 2187 + 6561 a{(r^{n}  1)/(r  1)}, a is first term, r is common ratio, n is number of terms 3 * {(3^{8}  1)/(3  1)} The sum of the series is 9840 
Post/View Answer
Post comment
Cancel
Thanks for your comment.!
Write a comment(Click here) ...

View in English View in Hindi 
Shantanu was given a task of adding a certain number of consecutive natural numbers starting from 1. By mistake, he missed a number during addition. He obtained the sum as 800. Find the number that he missed? 
A) 15
B) 20
C) 25
D) 10
Correct Answer : 20 Explanation : Sum of n natural numbers is n(n+1)/2 ,and let missing number is x (x<=n) ,then 
A two digit number is such that the product of its digits is 12. When 9 is added to the number, the digits interchanges their places, find the number? 
A) 62
B) 34
C) 2
D) 43
Correct Answer : 34 Explanation : lets the digits of number are x and y, where x is tenth digit.then number would be 10x+y After putting eq2 in eq1 , the eq1 would be Suppose x= 3, then y=4 .Then number would be 34.when add 9 in 34 it would be 43, which is reversed of 34. 
What is the sum of first 10 prime numbers? 
A) Even
B) Odd
C) Can’t say
D) None of these
Correct Answer : Odd Explanation : first ten prime numbers are 2, 3, 5, 7, 11, 13, 17, 19, 23, and 29. 
If 43571A98B is a ‘9’ digit number divisible by 72. Which of the following is true for A and B ? 
A) A>B
B) A=B
C) A<B
D) Can’t be determined
Correct Answer : A=B Explanation : if 43571A98B is divisible by 72 then it should be divisible by coprime of 72. 43571A98B divisible by 8. now, 43571A984 to be divisible by 9. Therefore, 43571A98B is divisible by 72 when A and B shuld be 4 , i.e. A=B<=>4 
A 4 digit number is formed by repeating a 2 digit number such as 2424, 1212 etc. Any number of this form is always exactly divisible by? 
A) 7
B) 11
C) 13
D) 101
Correct Answer : 101 Explanation : Let the unit digit x and tenth digit y , So, that number must be divisible by 101, also 101 is the smallest threedigit prime number. 
The product of two numbers is 192 and the difference is 4. These two numbers are? 
A) 16, 12
B) 18, 14
C) 17, 13
D) 15, 11
Correct Answer : 16, 12 Explanation : let the numbers are x and x4 that both sets of answers will work. (12 * 16) = 192 , (12 * 16) = 192 

(422+404)^{2}−(4×422×404) = ? 
A) 344
B) 342
C) 324
D) 312
Correct Answer : 324 Explanation : (a+b)^{2}  (ab)^{2} = 4ab Hence ,^{ }(422+404)^{2}−(4×422×404) => (422  404)^{2 }=> (18)^{2 }=> 324 
What is the largest 4 digit number exactly divisible by 88? 
A) 9944
B) 9999
C) 9988
D) 9900
Correct Answer : 9944 Explanation : Largest 4 digit number = 9999 
The sum of, 1+2+3+⋯+12=? 
A) 66
B) 68
C) 76
D) 78
Correct Answer : 78 Explanation : Sum=1+2+3+⋯+n= n(n+1)/2 

If the 4th term of an arithmetic progression is 17 and the 7th term is 26, what is the 12th term? 
A) 33
B) 37
C) 41
D) 53
Correct Answer : 41 Explanation : 4th term of AP , a4 = a + 3d where a is 1st term & d is common difference,then 
The 17th term of the arithmetic progression whose first two term are –3 and 2 is? 
A) 136
B) 82
C) 77
D) 120
Correct Answer : 77 Explanation : as given first two term of AP are –3 and 2 , So a is 1st term that is 3 and the 2nd term a+d = 2 (d is common difference), then So 17th term of AP is = a + 16d 
The 7th term of an AP is 5 times the first term and its 9th term exceeds twice the 4th term by 1. The first term of the AP is ? 
A) 151
B) 39
C) 3
D) 124
Correct Answer : 3 Explanation : 7th term , A + (7–1)d = 5A as given, A + (9–1)d = 2[A + (4–1)d] + 1 after solving (i) and (ii) we get d = 2, A = 3 
Which of the following is a multiple of 88 ? 
A) 1392578
B) 138204
C) 1436280
D) 143616
Correct Answer : 143616 Explanation : Only 143616 is a multiple of both 11 and 8 so it is a multiple of 88. 
How many integers from 1 to 100 exist such that each is divisible by 5 and also has 5 as a digit ? 
A) 10
B) 12
C) 11
D) 20
Correct Answer : 11 Explanation : These numbers are following 
The sum of all prime numbers which is not greater than 17 .The sum is? 
A) 59
B) 58
C) 41
D) 42
Correct Answer : 58 Explanation : The sum is = 2+3+5+7+11+13+17= 58 
If 1 + 2 + 3 + .... + 100 = x, then find the value of x ? 
A) 5050
B) 5000
C) 10100
D) 10000
Correct Answer : 5050 Explanation : 1+2+3+4....+100= n(n+1)/2 