Question

find the sum of first 20 multiples of 10

Answer 1

Answer:

first 20 multiples of 10 are 10,20,30,40,50,60,70,80,90,110,120,130,140,150,160,170,180,190 and 200

sum of it is 2000

Answer 2

Answer :

2100

step by step explanation :

1. 10,20,30............200.

(20 multiples of 10)

2. they are in A.P ( arithmetic progression )

so Sn = N/2 [2a +(n-1)d]

3. Here N=20 ,a =10 ,d=10

4. Sn=20/2 [2(10)+(20-1)10]

5.answer 2100