Question

The number of terms of the AP 7, 4, 1, -2,… -65 is​

Answer 1

Answer:

25

Step-by-step explanation:

The given AP is 7, 4, 1, -2,… -65

from this we get the following:

first term, a = 7

common difference, d = 4 - 7= -3

last term, aₙ = -65

nth term of an AP is given by

aₙ = a + (n - 1)d

substitute values, we get,

-65 = 7 + (n - 1) (-3)

-65 = 7 - 3n + 3

-3n + 10 = -65

-3n = -65 -10

-3n = - 75

3n = 75

n = 75/3

n = 25