Question

Last term of the arithmetic progression 8,15,22 is 218. Find the number of terms.​

Answer 1

Answer:

31

Step-by-step explanation:

here a1 is 8 and a2 is 15

common difference, d = a2 - a1

d = 15 - 8

d = 7

last term is l = 218

we know

l = a + (n-1)*d

218 = 8 + (n-1)*7

218 - 8 = (n-1)*7

210 = (n-1)*7

(n-1) = 210/7

(n-1) = 30

n = 30 + 1

n = 31

hence total number of terms is 31