Help Please! The question is linked below

The holiday party will cost $160 if 8 people attend.if there are 40 people who attend the party, how much will the holiday party cost

Given that sin∅ = 1/4, 0 < ∅ < π/2, what is the exact value of cos∅? a. (√4)/4 b. (√15)/4 c. (4π)/2 d. (4√2)/4

What number is 7 units left of -15?