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

I think 4! x 3! x 2! x 3!/9 which is 24x2x2x2 which is 24x8 do the calculation yourself

ratio of people: 5/6

ratio of work time: 6/5 = x/x-4

x = 24so 4 days - 25 more people

I agree - 2^2 is 4, by the way

wait, you made a error - you need to subtract the 6 ways all four are together 3 times, as that was quadruple counted

use similar triangles - x/1-x = 3-x/x, x^2 = 3-4x+x^2, x = 3/4

hope that helps!