Question

The (n - 1)^th term of an A.P. is given by 7, 12, 17, 22,… is ______.

Options

• 5n + 2

• 5n + 3

• 5n - 5

• 5n - 3

Answer 1

The (n - 1)^th term of an A.P. is given by 7, 12, 17, 22,… is 5n - 3.

Explanation:-

Here a = 7, d = 12 - 7 = 5

∴ a_n-1 = a + [(n - 1) - l]d

= 7 + [(n - 1) - 1](5)

= 7 + (n - 2)5

= 7 + 5n - 10

= 5n - 3