Question

1+(1+2)+(1+2+3)+(1+2+3+4)+...... find the sum of the following series to n terms​

Answer 1

Answer:

20

Step-by-step explanation:

1+(1+2)+(1+2+3)+(1+2+3+4)= 1+(3)+(6)+(10)=4+16=20Answer

Answer 2

Step-by-step explanation:

1+3+6+10.....

their difference are in arithmetic progression

s(n)=1/2((n×n+1)/2)+n(n+1)(2n+1)/6

hope you understand please Mark this

as the brainliest