Question

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

Answer 1

Answer:

210 is the answer

Step-by-step explanation:

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Answer 2

Answer:

this can be solved by AP

a= 1

d=1

l = 20

n=2

Sn=n/2(a+l )

Sn=10 (21)

=210

Step-by-step explanation:

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