Question

If 1+2+3+....+n=666 find n

Answer 1

Answer:

I hope it will help you...

Answer 2

Answer:

by using arithematic progression

a= 1

d= 1

and Sn (sum of terms) = 666

= n/2(2a+ (n-1)d)= 666

n(2+ n-1)= 1332

n^2- n - 1332=0

n^2-37n + 36n - 1332=0

n(n-37)+36(n-37)=0

(n-37)(n+36)=0

n=37 or n= - 36

But n cannot be negative

So n=37

Sorry by mistake done wrong please follow the first answer