Verbal Reasoning - Series Completion - Discussion

Discussion Forum : Series Completion - Section 1 (Q.No. 38)
Directions to Solve

Choose the correct alternative that will continue the same pattern and replace the question mark in the given series.


38.
1, 5, 14, 30, 55, 91, ?
130
140
150
160
Answer: Option
Explanation:

The pattern is + 4, + 9, + 16, + 25, + 36, ..... i.e. + 22, + 32, + 42, + 52, + 62,.....

So, missing term = 91 + 72 = 91 + 49 = 140.

Discussion:
1 comments Page 1 of 1.

SRINIVASAN G (AMACE) said:   1 decade ago
Format is,

1^2 + 2^2 + 3^2 + 4^2 + 5^2 + ...

For n=1, the sum is 1^2 = 1.

For n=2, the sum is 1^2+2^2 = 1+4 = 5.

For n=3, the sum is 1^2+2^2+3^2 = 1+4+9 = 14.

For n=4, the sum is 1^2+2^2+3^2+4^2 = 1+4+9+16 = 30.

For n=5, the sum is 1^2+2^2+3^2+4^2+5^2 = 1+4+9+16+25 = 55.

For n=6, the sum is 1^2+2^2+3^2+4^2+5^2+6^2 = 1+4+9+16+25+36 = 91.

For n=7, the sum is 1^2+2^2+3^2+4^2+5^2+6^2+7^2 = 1+4+9+16+25+36+49 = 140.

ANSWER IS 140

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