Answer:
A.
Step-by-step explanation:
So we want the ratio of the food amount in Daisy's bowl (D) to the food amount in Rufus's bowl (R) at time t.
So we are asked to do:
[tex]\frac{D}{R}[/tex]
[tex]\frac{400-120t}{450-150t}[/tex]
Let's see if we can simplify any.
Every single term on top and bottom have a common factor of 10 since they each contain a factor that ends in 0.
I'm going to divide top and bottom by 10:
[tex]\frac{40-12t}{45-15t}[/tex]
The answer is A.
I can see no more common factors between 40,12t,45, and 15t:
40=2(2)(2)(5)
12t=2(2)(3)t
45=3(3)(5)
15t=3(5)t
They don't all contain a common factor when looked at altogether.