Answer: 
Step-by-step explanation:
Given
For 30 ml of orange Juice
45 ml of apple Juice is needed and
25 ml of coconut milk is required
The proportion of coconut milk in the cocktail is
C(x) = 400 + 20x - 0.2x²
c(30) = 400 + 20(30) - 0.2(30)²
= 400 + 600 - 0.2(900)
= 1000 - 180
= 820
It costs $820 when 30 radios are produced.
Marginal cost is how much it would cost to make one MORE of the same product so now we find how much it costs to produce 31 radios and compare the two.
c(31) = 400 + 20(31) - 0.2(31)²
= 400 + 620 - 0.2(961)
= 1020 - 192.2
= 827.8 or ≈828.
Now we find the difference which means we subtract the two.
828 - 820 = 8.
Your marginal cost is $8.
To compare we can also do 29 radios.
c(29) = 400 + 20(29) - 0.2(29)² = 811.8 or ≈812
820 - 812 = 8.
In the given question, we come to know that Sammy sold 5 bottles for every 3 water bottles sold by David. In this case we get the ratio as 5:3
Now this ratio indicates that the total number of bottles can be divided into 8 parts for finding out a single part. the total number of water bottles that are sold by Sammy and David together are 160.
Now on dividing this total number of bottles by 8 we get the 20 as one part.
The,
Number of Bottles sold by Sammy = 5 * 20
= 100
Number of bottles sold by David = 3 * 20
= 60
So Sammy sold 100 water bottles and David sold 60 water bottles from the total of 160 water bottles.
