Find the 20th term from the last term of the AP: 3, 8, 13, …. 253.

In the given series first term a = 253

and, common difference d = 248 - 253 = -5

We know that the nth term of an AP is defined by an = a + (n - 1)d

So, to evaluate the 20th term we will calculate a20

a20 = 253 + (20 - 1) (-5)

a20 = 253 - 95

a20 = 158

A succession of terms with a common difference between them that has a constant value is known as an arithmetic progression. It is employed to generalise a collection of trends that we notice in daily life. As an illustration, AP is used to forecast any sequence, such as when a person is waiting for a cab. He or she can anticipate when the next taxi will arrive assuming that traffic is moving at a steady speed.

Summary:

Find the 20th term from the last term of the AP: 3, 8, 13, …. 253.

The 20th term from the last term of the AP: 3, 8, 13, …. 253 is 158. When any two succeeding numbers in a series diverge consistently from one another, the sequence of numbers is referred to as a "arithmetic progression" (AP).