Question Details

Select the number from among the given options that can replace the question mark (?) in the following series.
62, 74, 80, 86, 95, ?, 158

Options

A

100

B

108

C

122

D

113

Show Answer

Correct Answer :

Option D

113

113

Solution :

The correct answer is 113.

To find the missing number, we first calculate the differences between consecutive terms in the series:

62  →  74  →  80  →  86  →  95  →  ?  →  158

Differences:
74 - 62 = 12
80 - 74 = 6
86 - 80 = 6
95 - 86 = 9
? - 95 = d₅
158 - ? = d₆

So the sequence of differences so far is: 12, 6, 6, 9, d₅, d₆

Now, let's examine the ratios of consecutive differences (i.e., how each difference relates to the one before it):

6 ÷ 12 = 0.5
6 ÷ 6 = 1.0
9 ÷ 6 = 1.5
d₅ ÷ 9 = 2.0   (following the pattern)
d₆ ÷ d₅ = 2.5   (following the pattern)

The ratios form a clear arithmetic progression: 0.5, 1.0, 1.5, 2.0, 2.5, ... — increasing by 0.5 each time.

Using this pattern to find the missing differences:

d₅ = 9 × 2.0 = 18
d₆ = 18 × 2.5 = 45

Now we can verify:

? = 95 + 18 = 113
158 = 113 + 45 = 158 ✓

The complete series with all differences verified:

62  (+12)  74  (+6)  80  (+6)  86  (+9)  95  (+18)  113  (+45)  158

Therefore, the missing number that replaces the question mark is 113.

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