If 4, x1, x2, x3, 28 are in AP then x3 = ?

Q4 of 178 Page 559

If 4, x₁, x₂, x₃, 28 are in AP then x₃ = ?

Here, first term = a = 4

Last term = l = 28

Number of terms = n = 5

∴ l = a + (n - 1)d

⇒ 28 = 4 + (5 - 1)d

⇒ 28 - 4 = 4d

⇒ 4d = 24

⇒ d = 6

Therefore x₃ = a + 3d

= 4 + 3(6)

= 4 + 18

= 22

The common difference of the AP is

The next term of the AP is

If the nth term of an AP is (2n + 1), then the sum of its first three terms is

The sum of first n terms of an AP is (3n² + 6n). The common difference of the AP is