Question

28. Find the 15th term of AP if its Ist term & common difference be20, -10 respectively
O A. 110
O B.-120
O C. -105
D. -100
ما​

Answer 1

Answer:

(B) -120

Step-by-step explanation:

As given in the question,

a = 20

d = -10

n = 15

To find the nth term in an AP, we use the formula

T(n) = a+(n-1)d

T(n) = 20 + (15-1)×(-10)

T(n) = 20 - 14×10

T(n) = 20-140

T(n) = -120