75%x35%=3/4x7/20=21/80 of it's total matches for the season won. you need 19/80, or 19/20 of 1/4, so the answer is 19/20
1/4+1/70+1/77
1/70+1/77=21/770=3/110
3/110+1/4 = 61/220
correct me if i'm wrong!
for 3 it's the easiest find the side lengths ratio - because the pyramid has 3 45-45-90 triangles, and cube it, multiply by 4, and substract from original cube
for 2 there's a formula for volume of a tetrahedron knowing only all six side lengths - it appears in murdereous maths, and just plug the sidelengths in - inefficient to do that tho
for 1. try find the ratio of the side lengths using the pythogorean theorem, and also properties of equilateral triangles
