Solution:

If A.P. is 3, 8, 13,…, 253, then the common difference is d= 5.

As a result, we can rewrite the given AP as follows:

253, 248, 243, …, 13, 8, 5

For the new AP,

the first term is a = 253

and the common difference is d = 248 253 = 5.

n = 20

Therefore, using nth term formula, we get,

a₂₀ = a+(20−1)d

a₂₀ = 253+(19)(−5)

a₂₀ = 253−95

a = 158

As a result, the 20th term from the AP 3, 8, 13,…, 253.is 158.