Question

which term of the following is AP is 551 are 2, 11, 20, 29​

Answer 1

Answer:

a = 2

d = 11-2 = 9

tn = a + ( n - 1 ) d

551 = 2 + ( n - 1 ) 9

551 = 2 + 9n - 9

551 - 2 + 9 = 9n

558 = 9n

n = 558 / 9

n = 62

Answer 2

GIVEN

The Arithematic Progression is 2,11,20...

The First Term, a = 2

The Common Difference, d = a2 - a1

=> 11 - 2 = 9

One general term 551 is given.

TO FIND :- Number of term, n

SOLUTION

We know that the general term formula of an A.P. is

an = a+ (n - 1)d

=> 551 = 2 + ( n - 1)9

=> 551 - 2 = (n - 1)9

=> 549 = (n - 1)9

=> 49 = 9n - 9

=> 558 = 9n

=> n = 62

Here n = 62

Hence the 62th term of given A.P. is 551. (ANS)