Okay so the problem starts you off with the fraction (1/4). Sharing equally among 3 people would mean that you'd want to divide it by three so your equation would initially look like (1/4) / 3. Having two dividing signs is confusing so what you do is change the dividing into multiplying by the reciprocal of 3 = 1/3... This would make your expression (1/4) * (1/3) and when you simplify this you should get 1/12 as the answer.
4:1/6 if you add all the instruments you get 120 then you divide it by six and you get 20 snare drums
Let's turn this sentence into an equation:
8n = -n + 36
Then solve:
9n = 36 => n=4
