Answer:
the last one
Step-by-step explanation:
If you start with a 12x16 rectangle and cut square with side length x, when you bend the sides you'll have an inner rectangle with sides
and
, and a height of x.
So, the volume will be given by the product of the dimensions, i.e.

The derivative of this function is

and it equals zero if and only if

If we evaluate the volume function at these points, we have

So, the maximum volume is given if you cut a square with side length

Susanne is 16 years old.
b = Bob's age
s = Susanne's age
d = Dakota's age
Bob's age is 4 times greater than Susanne's age:
b = 4s
Dakota is three years younger than Susanne:
d = s - 3
The sum of Bob's, Susanne's, and Dakota's ages is 93:
b + s + d = 93
solve these equations:
b = 4s
d = s - 3
b + s + d = 93
and get:
b = 64 years
s = 16 years
(remember that s = Susanne)
d = 13 years
You would know because for example, if it's out of 4 and the fraction said 4/4, that would mean one. 3/3 would mean one. 2/2 and so on