Correct Answer - Option 3 : 8
th
Given:
-22, -19, -16... is Arithmetic Progression
Formula used:
nth = [a + (n - 1) × d]
Where a is the first number in the series
d is the common difference
Calculation:
The common difference is
⇒ d = -19 - (-22) = 3
The term need to be lesser than zero
⇒ nth = - 22 + (n - 1) × 3
⇒ nth = - 25 + 3n < 0
⇒ nth = 3n < 25
⇒ n < 25/3
⇒ n < 8.33
So n = 8
nth = -22 + (8 - 1) × 3 = -1
which is the last negative number.
∴ So the last negative term is 8th term.