1 / 1 + 2 + 1 / 1 + 2 + 3 + 1 / 1 + 2 + 3 + 4 + +1/1+2+3+…… +20 = m / N. where m and N are positive integers and have no common divisor. Find m + n

1 / 1 + 2 + 1 / 1 + 2 + 3 + 1 / 1 + 2 + 3 + 4 + +1/1+2+3+…… +20 = m / N. where m and N are positive integers and have no common divisor. Find m + n

1/1+2+1/1+2+3+1/1+2+3+4+…… +1/1+2+3+…… +20
=2/2×3+2/3×4+2/4×5+.+2/20×21
=2 （1/2-1/3+1/3-1/4+.+1/20-1/21）
=2×（1/2-1/21）
=1-2/21
=19/21
m=19,n=21
m+n=40

Elden Ring Premiere

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