Question

Which term of the ap 3 1, , 2 21 3, , 0. Will be 90 more than its 50th term

Answer 1

Answer:

AP: 3,12,21,30

a=3

d=9

a50= a+49d

      = 3+49×9

      = 3+441

      = 444

an=a50+90

a+(n-1)d = 444+90

3+(n-1)9 = 534

(n-1)9 = 531

n-1 = 531/9 = 59

n=60

Answer 2

Given,

An A.P 3,12,21,30,...

To Find,

The term which is 90 more than the 50th term.

Solution,

In the given A.P

a = 3

d = 12-3 = 9

So,

a₅₀ = a+49d = 3+49*9 = 3+441 = 444

Let there be an nth term which is 50 more than the 50th term.

So,

aₙ = a+(n-1)d = 90+a₅₀

3+(n-1)9 = 90+444

3+9n-9 = 534

9n-6 = 534

9n = 540

n = 60

Hence, the 60th term of the given A.P is 90 more than the 50th term.