This corresponds to a sinusoidal graph, we have:
Radius= 20 feet, that corresponds to the amplitud (A)
One revolution takes 24 seconds, that corresponds to the period
Min= 3 feet
k=360/24=15
D= bottom distance+ amplitud=3+20=23 feet

Then, let x be the time, in seconds:

a) To determine Reid's height after 1 minute= 60 seconds, substitute x=60

b) To determine when Reid's height will first reach 18 feet, we have to substitute y=18 feet, and isolate x:
So the question is 16 is 25% of what number (x)
In math
"is" means equals
"of" means times
The question translates to
16 = 25% * x
16 = .25x
16/.25 = x
64 = x
x = 64
16 is 25% of 64
To find the price per shirt, simply divide the total (combined) cost of the shirts by the amount of shirts
A.) $26.96 (cost of 6 shirts) ÷ 6 (shirts) = $4.49 per shirt
B.) $21.00 (cost of 5 shirts) ÷ (5 shirts) = $4.20 per shirt
C.) $28.50 (cost of 7 shirts) ÷ (7 shirts) = $4.07 per shirt
Comparing A, B, and C, the best buy would be C ($28.50 for 7 shirts)
2y=3(-x+5)
Distributed property
2y= -3x +15
Move x term to left side to get
3x+2y=15