What will come in the place of question mark (?) in the following number series? 2, 3, -1, 8, -8, ?
17
Find the differences between consecutive terms: 3 − 2 = +1, −1 − 3 = −4, 8 − (−1) = +9, −8 − 8 = −16.
The differences are +1, −4, +9, −16, i.e. +12, −22, +32, −42 — squares with alternating signs.
The next difference is +52 = +25.
Next term = −8 + 25 = 17.
Hence, the missing number is 17.
Similar Questions
Which number breaks the sequence?
0, 1, 1, 2, 4, 8, 13
Monthly savings were 4000, 4400, 4840, and 5324.
Estimate the savings in the sixth month if the same trend continues.
The number of subscribers increased consistently by 10% yearly: 5000, 5500, 6050, 6655, and 7320.
The estimate for the 7th year is
Important Questions from Number Series
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
