Question

find first 20 numers sum​

Answer 1

let,

n=20

d=1

a=1

Sn=n/2 2a+(n-1)d

S20=20/2 2(1)+(20-1)1

S20=10 2+19

S20=10.21

S20=210

sum of first 20 no. are 210

Answer 2

Answer:210

Step-by-step explanation:

1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20= 210