Répondre :
1 cube=1 marche
1+2+3 cubes=2 marches
1+2+3+4+5 cubes=3 marches
1+2+3+...+(2n-1) cubes =n marches
(1+2n-1)(2n-1)/2 cubes = n marches
n(2n-1) cubes = n marches
100x(200-1) cubes = 100 marches
19900 cubes = 100 marches
1+2+3 cubes=2 marches
1+2+3+4+5 cubes=3 marches
1+2+3+...+(2n-1) cubes =n marches
(1+2n-1)(2n-1)/2 cubes = n marches
n(2n-1) cubes = n marches
100x(200-1) cubes = 100 marches
19900 cubes = 100 marches