Question : Directions: Select the number from among the given options that can replace the question mark (?) in the following series.
57, 59, 56, 60, ?, 61, 54
Option 1: 55
Option 2: 53
Option 3: 54
Option 4: 63
Correct Answer: 55
Solution :
Given:
57, 59, 56, 60, ?, 61, 54
Add and subtract consecutive natural numbers alternately in the previous number to obtain the next number.
57 + 2 = 59; 59 – 3 = 56; 56 + 4 = 60; 60 – 5 = 55; 55 + 6 = 61; 61 – 7 = 54
So, the missing number is 55. Hence, the first option is correct.
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