Well if each portion is 3 pounds and there is 4 portions all together it would be 12 pounds. you already know know that the meat is 2 pounds so you subtract 2 from the whole and you are left with 10. The chopped vegetables are 10 pounds in total.
The answer is
4x3=12-2=10
is strictly increasing on [0, 5], so

and

so the integral is bounded between

Answer:
(only ii right?)
Since we have the total number is 360° and our section is 72°, we know that the percentage of students who choose the cinema should be the number that we have divided to the total amount and then multiply the result by 100 ( it's fine if you write 100%, but when you actually calculate it, it's only 100, not 100%):
(72/360) . 100 = 20%
To find the other endpoint with a given endpoint and midpoint, you subtract the midpoint values from the endpoint, then with whatever the answer is, you subtract that from the midpoint.