3, −2, −12, −32, −72, ?
The given number series is: 3, −2, −12, −32, −72, ?
Calculate the differences between consecutive terms to identify a pattern.
| Term Pair | Difference ($a_{n+1} - a_n$) |
| 3 and −2 | $-2 - 3 = -5$ |
| −2 and −12 | $-12 - (-2) = -10$ |
| −12 and −32 | $-32 - (-12) = -20$ |
| −32 and −72 | $-72 - (-32) = -40$ |
The calculated differences are: $-5, -10, -20, -40$.
Notice that each difference is twice the previous difference:
Following this pattern, the next difference is $-40 \times 2 = -80$.
To find the missing term (the next term in the series), add this next difference ($-80$) to the last term of the series ($-72$).
Missing Term = Last Term + Next Difference
Missing Term = $-72 + (-80)$
Missing Term = $-72 - 80$
Missing Term = $-152$
Select the number from among the given options that can replace the question mark (?) in the following series.
5, 18, 39, 68, 105, ?
What will come in place of question mark (?) in the following number series?
2, 5, 11, 23, 44, 77, ?
What will come in place of question mark (?) in the following number series?
31, 32, 36, ?, 61, 86
What will come in the place of question mark (?) in the following number series?
3, 6, 18, ?, 630, 6930
What should come in place of the question mark ‘?’ in the following number series?
60, 40, 50, ?, 180, 460
A series is given with one term wrong. Select that wrong term from the given alternatives.
J12, M24, P48, S96, U192