They will use 250 ml of vingaer
Let the water surface be 0.
He starts at 15 and gets to the water surface of 0 so he travels 15 meters.
He then goes 5 meters below the surface.
15 + 5 = 20 total meters.
Answer: 
<u>Step-by-step explanation:</u>
cos x tan x - cos x = 0
cos x (tan x - 1) = 0
cos x = 0 tan x - 1 = 0
tan x = 1
Perimeter = 2 times the Length + 2 times the Width
Using Excel formulas
=LARGE(A1:A20, 1)/COUNT (A1:A20)
Count (Ai:An) Function that allows to count the total number of values in a cells range between Ai and An that contain only numbers.
Large (Ai:An, k) Function that allows to find the value of the largest number in a cells range between Ai and An, the number k determine the k-th largest value
