allery2, ?, 12, 20, 30 में एक संख्या लुप्त है। वह लुप्त संख्या क्या है?
A6
B8
C4
D10
Answer & Solution
Correct answer: A. 6
पद n × (n + 1) के अनुसार हैं: 1×2, 2×3, 3×4, 4×5, 5×6, इसलिए दूसरा पद 6 है।
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