Number Series Questions

Q:

What is the next number of the following sequence ?

21, 77, 165, 285, ......

A) 404 B) 415
C) 426 D) 437
 
Answer & Explanation Answer: D) 437

Explanation:

The series follow the rule,

 


21 = 
77 = 92-4
165 = 132-4
285 = 172-4


5,9,13,17,21,(+4)...
In the same way next no. will be
212-4 = 441 - 4 = 437

Report Error

View Answer Report Error Discuss

44 38891
Q:

8, 15, 28, 53, ?, 199

A) 101 B) 102
C) 103 D) 104
 
Answer & Explanation Answer: B) 102

Explanation:

Here the series of the form is x2 - 1, x2 - 2, x2 - 3,...

 53 x 2 - 4 = 106 - 4 = 102

Report Error

View Answer Report Error Discuss

321 36566
Q:

Find out the wrong term in the series 2, 3, 4, 4, 6, 8, 9, 12, 16

A) 9 B) 12
C) 16 D) 8
 
Answer & Explanation Answer: A) 9

Explanation:

The given sequence is a combination of three series:
i)1st, 4th, 7th terms i.e, 2, 4, 9
ii)2nd, 5th, 8th terms i.e, 3, 6, 12
iii)3rd, 6th, 9th terms i.e, 4, 8, 16
In each one of i, ii, iii, each term is twice the preceding term.
So, 9 is wrong and must be replaced by (4*2) = 8

Report Error

View Answer Report Error Discuss

404 34956
Q:

Find the wrong number in the series

7, 28, 63, 124, 215, 342, 511

A) 28 B) 124
C) 215 D) 342
 
Answer & Explanation Answer: A) 28

Explanation:

Here the number follows the given rule 

 23-1, 33-1, 43-1, 53-1, ...

 

But 28 has been given in problem series.

 

so 28 is wrong number.

Report Error

View Answer Report Error Discuss

125 32441
Q:

7, 8, 18, 57, ?, 1165, 6996

A) 228 B) 542
C) 232 D) 415
 
Answer & Explanation Answer: C) 232

Explanation:

Here 2nd number = (1st number x 1 )+1

 3rd number = (2nd number x 2 +2) 

4th number = (3rd number x 3 )+3 and so on..

 

Therefore, 5th number = (4th number x 4) +4 =57 x 4 + 4 =232.

Report Error

View Answer Report Error Discuss

165 30749
Q:

Find the missing number in the following series?

2, 3, 10, 39, ?, 885

A) 128 B) 156
C) 172 D) 189
 
Answer & Explanation Answer: C) 172

Explanation:

Take a Look at the below sereies

2×1+12=3

3×2+22=10

10×3+32=39

39×4+42=172

172×5+52=885

Report Error

View Answer Report Error Discuss

69 29203
Q:

Find the missing term in the following series ?

10000, 11000, 9900, 10890, ?, 10781

A) 10423 B) 9801
C) 10241 D) 9712
 
Answer & Explanation Answer: B) 9801

Explanation:

Clearly, alternatively we add and subtract 10% of a term to obtain the next term of the series.
Thus, 10000 + (10% of 10000)= 11000;
11000 - (10% of 11000) = 9900;
 9900 + (10% of 9900)  = 10890;
10890 - (10% of 10890) = 9801.
 9801 + (10% of 9801)  = 9801+980 = 10781.
So, missing term = 10890- (10% of 10890)= 9801.

Report Error

View Answer Report Error Discuss

90 27237
Q:

Choose the missing terms out of the given alternatives Z, X, S, I, R, R, ?, ?

A) J, I B) K, M
C) G, I D) J, K
 
Answer & Explanation Answer: C) G, I

Explanation:

Z - 2 = X
X - 5 = S
S - 10 = I
I - 17 = R
R - 26 = R
R - 37 = G
G - 50 = I
The series 2, 5, 10, 17, 26, 37, 50 is obtained by the pattern +3, +5, +7, +9, . . . .

Report Error

View Answer Report Error Discuss

187 27218