Question

21th term of the AP - 12,-8. - 4...
1) 62
2) 60
3) 76
4) 72​

Answer 1

Answer:

Given options have a mistake, if I am correct.

All the best!

Hope it helps!

Answer 2

Answer:

The 21ˢᵗ term of the A.P. is 68.

Step-by-step-explanation:

The given AP is - 12, - 8, - 4, ....

a = t₁ = - 12

d = t₂ - t₁ = - 8 - ( - 12 ) = - 8 + 12 = 4

We have to find the 21st term of the A.P.

We know that,

tₙ = a + ( n - 1 ) * d - - - [ Formula ]

⇒ t₂₁ = - 12 + ( 21 - 1 ) * 4

⇒ t₂₁ = - 12 + 20 * 4

⇒ t₂₁ = - 12 + 80

⇒ t₂₁ = 68

∴ The 21ˢᵗ term of the A.P. is 68.