Answer:
1 and 7/8 in two hours
Step-by-step explanation:
So Volume of cylinder is pi*r^2*h = 1,000
Then lightest one means you have the smallest surface area. Which is one base and then the area of the surface. SA = pi*r^2 + 2pi*r*h
So now you have 2 equations, so:
h = 1,000/(pi*r^2)
So then SA = pi*r^2 + 2pi*r*(1,000/(pi*r^2) = pi*r^2 + 2,000/r
Derivative of SA is then 2pi*r -2,000/r^2. Set to 0
2pi*r-2,000/r^2 =0 --> 2pi*r^3 = 2,000 --> r^3 = 1,000/pi --> r = 10/pi^(1/3)
Now go back to the volume function: pi*r^2*h =1,000 --> 1,000/(pi*100/pi^(2/3)) = h
<span>h = 10 / pi^(1/3)</span>
The answer is x=7 and y=3
Automatically we know that he is wrong because even if we round it to make it a friendly number (lets say 1) it will still not equal 3 1/2
he has them for 3 1/2 days
even 1+1+1= 3 it still isnt enough and you arent even supposed to round
That is why he is wrong :) hope this helped
