Q1 of 176 Page 8

Find the indicated terms in each of the following arithmetic progression:
a = 21, d = — 5; t_n, t₂₅

Given: a = 21 , d = –5

To find: t_n and t₂₅

We have,

t_n = a + (n – 1)d

t_n = 21 + (n – 1)(–5)

= 21 – 5n + 5

t_n = 26 – 5n

Now, n = 25

So, t₂₅ = 21 + (25 – 1)(–5)

= 21 + 24 × (–5)

t₂₅ = 21 – 120

t₂₅ = –99

Find the indicated terms in each of the following arithmetic progression:

a = 3, d = 2; ; t_n, t₁₀

Find the indicated terms in each of the following arithmetic progression:

— 3, — 1/2, 2, ... ; t₁₀,

Find the 10th term of the A.P. 10, 5, 0, — 5, — 10, ...

Find the 10th term of the A.P.

Find the indicated terms in each of the following arithmetic progression:a = 21, d = — 5; tn, t25