Question

Find the sum of the first 32 terms of the AP : 0.5, 0.75, 1​

Answer 1

`S_(32)` = 140

Explanation:

The sum of n terms of an AP is

`S_(n)` =
`(n)/(2)` [ 2a₁ + (n - 1)d ]

where a₁ is the first term and d the common difference

Here a₁ = 0.5 and d = a₂ - a₁ = 0.75 - 0.5 = 0.25 , then

`S_(32)` =
`(32)/(2)` [ (2 × 0.5) + (31 × 0.25) ]

= 16(1 + 7.75)

= 16 × 8.75

= 140