Which number can replace the question mark in the series 1, 7, 17, 31, ?, 71
A47
B49 ✓ Correct
C41
D60
Correct answer: (B) 49
Explanation
The missing term is 49.
differences are 6, 10, 14, 18, 22.
each gap rises by 4.
term = 31 + 18 = 49.
check: 49 + 22 = 71, the last term.
Want more like this? Create a free account to practise a full test, track your progress, and get spaced-repetition review.
Practise on Mcqkart →🎓 Book an expert →