Julie would reach her goal first. Julie would reach her goal in approximately 316 days while it would take Mary approximately 333 days to reach it.
I know this because the steps to solve the problem are:
1.) 1,000/12 = 83.333 (to find how many days it would take her everyday)
2.) 83.333x4 = 333 (multiplying the answer by four makes it every four days)
3.) determine that it takes Mary 333 days
4.) 1,000/19 = 52.631 (just like step 1 but with different numbers)
5.) 52.631x6 = 316 (just like in step 2 but different numbers)
6.) determine it takes Julie 316 days
7.) 316 < 333 (takes Julie less time)
Check the picture below. Recall, is an open-top box, so, the top is not part of the surface area, of the 300 cm². Also, recall, the base is a square, thus, length = width = x.

so.. that'd be the V(x) for such box, now, where is the maximum point at?

now, let's check if it's a maximum point at 10, by doing a first-derivative test on it. Check the second picture below.
so, the volume will then be at
So the object of this problem is to find out the value of d.
To do this, first think about 5 + 3. This equals 8, right? So the value of d times 4 has to equal 8.
No other number besides 2 would make sense. 2 would equal d because 4 x 2 is 8, and 5 + 3 is 8.
So you would write the answer as:
5+3=4(2)
(-3,9) The x axis is -3 and the y axis is 9