Question

5th term of an arithmetic sequence is 38 and 9th term is 66
Which term of the sequence is 185?

Plz explain

Answer 1

Step-by-step explanation:

A(5) = a + 4d = 38 -------(1)

A(9) = a + 8d = 66 -------(2)

from equation (2) - (1)

4d = 28

d = 7

a = 38 - 4(7) = 38 - 28 = 10

A.P. 10 , 17 , 24 ,..........

Let the nth term of this AP is 185

So , An = 185

a + (n - 1)d = 185

10 + (n - 1)7 = 185

7(n - 1) = 175

n - 1 = 25

n = 26

So , 26th term of above AP is 185 .