Question
In each of the following number series, one term is
missing. Find the missing term. 3, 8, 18, 35, 61, ?, 148Solution
Observe the differences: 8 - 3 = 5 18 - 8 = 10 35 - 18 = 17 61 - 35 = 26 ? - 61 = 37 148 - ? = 50 Now second differences are: 10 - 5 = 5 17 - 10 = 7 26 - 17 = 9 37 - 26 = 11 50 - 37 = 13 So the pattern follows +5, +7, +9, +11, +13 in second difference. Missing term = 61 + 37 = 98 Hence, the missing term is 98.
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