Since a log graph is with base 10 and a ln graph is with base e (2.something), the log x graph will clearly have smaller numbers (as, for example, log100=2 and ln100=around 4.6). In addition, you only have to multiply a number by e to increase the power by 1 but you have to multiply a number by 10 (which is significantly larger than e) to increase logx's power by 1, therefore proving that the log x graph will grow slower
We can use trigonometry. The cosine of 15 will be the side adjacent to the 15-degree side (the one we are looking for) divided by 20, the hypotenuse. As cos(15) is about .966, we get 19.32 as the side we are looking for.
Answer:
D. 
Step-by-step explanation:

Simply subtract the two functions from each other and simplify to get the result.
Check the picture below.
so the lunchbox is really a semi-circle with a radius of 3, sitting on top of a square of 6x6, with a lenght of 10.
the volume of the lunchbox then will be the area of the semi-circle and square times the length.