Question

find the sum of ap 20th term whose number are a=10 d=10?​

Answer 1

Answer:-

Sum of AP upto 20th term is 2100

Step by step explanation:

Given : In an AP, a = 10 and d = 10

To find : Sum upto 20th terms

Solution :

In the given question, we are asked to find the sum of AP upto 20th term. We know that AP (Arithmetic Progression) is a series which has same common difference between two preeceeding terms. Since we have to find the sum upto 20th term, value of n will be 20. First term and common difference are given in the question. We can easily find the sum of AP by applying formula.

So let's start!

Formula for sum of AP ::

→ Sn = n/2 [2a + ( n - 1 ) d ]

→ S20 = 20/2 [ 2 ( 10 ) + ( 20 - 1 ) ( 10 ) ]

→ S20 = 10 [ 20 + ( 19 )( 10 ) ]

→ S20 = 10 [ 20 + 190 ]

→ S20 = 10 [ 210 ]

→ S20 = 2100

So the required sum of 20 terms of AP is 2100.