Which of the following numbers would replace the question mark (?) in the given number series? 2, 10, 30, ?, 130
68
For a number series, the aim is to discover one consistent rule that reproduces every term already shown, so that the same rule can supply the missing value with confidence.
The terms 2, 10, 30, ?, 130 grow quickly, which hints at a cubic pattern rather than simple addition. A natural candidate linked to position \(n\) is \(n^{3}+n\).
Test it on the visible terms using positions \(n=1,2,3\): \(1^{3}+1=2\), \(2^{3}+2=8+2=10\) and \(3^{3}+3=27+3=30\), all matching.
The blank sits at position 4, so the rule gives \(4^{3}+4=64+4=68\).
The last visible term is a further safeguard: at position 5 the rule predicts \(5^{3}+5=125+5=130\), which is precisely the value printed.
Because the single rule \(n^{3}+n\) reproduces every known term without exception, the value it gives at position 4 must be the missing one.
Therefore the number that replaces the question mark is 68.
Similar Questions
What will be the 50th term in the following series?
20, 24, 28, 32, ....
A series is given with one term wrong. Select the wrong term from the given alternatives.
-913, -916, -924, -937, -955, -975, -1006, -1039
A series is given with one term missing. Select the correct alternative from the given ones that will complete the series.
11, 36, 147, ? , 1779, 5340, 21363
In the following question, four number pairs are given. In each pair the number on left side of (−) is related to the number of the right side of (−) with some Logic/Rule/Relation. Three pairs are similar on the basis of same Logic/Rule/Relation. Select the odd one out from the given alternatives.
(NOTE: Operations should be performed on the whole numbers, without breaking down the number into its constituent digits. E.g.13 − Operations on 13 such as adding /subtracting /multiplying etc. to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed)
Find the next element that replace the ? Logically
990, 1321, 1718, 2187, ?
Directions: Pick the correct options from below.
8, 18, 32, 50, ?
Identify the next number in the sequence.
8, 24, 48, 80, 120, ?
Which of the following numbers would replace the question mark (?) in the given number series?
11, 14, 19, 26, 35, ?
Find the next element that replace the ? Logically
90, 109, 130, 153, ?
Find the next element that replace the ? Logically
30, 41, 54, 69, ?
Important Questions from Number Based
In the following question, four number pairs are given. The number on left side of (-) is related to the number of the right side of (-) with some Logic/Rule/Relation. Three are similar on basis of same Logic/Rule/Relation. Select the odd one out from the given alternatives.
Select the set in which the numbers are related in the same way as are the number of the following set.
(3, 7, 58)
Find the odd number/letters from the given alternatives.
Find the odd number/letters from the given alternatives.
Identify the number which is different from the other.
