
<u>Step by step explanation:</u>
Step 1:

Step 2:

Step 3:

Step 4:

Step 6:

First, we have to get the fractions to common denominators.
4/5 = 16/20
1/4 = 5/20
5 5/20 - 3 16/20 = 1 9/20
She put 1 9/20 extra cups in.
Answer:
d. 15
Step-by-step explanation:
Putting the values in the shift 2 function
X1 + X2 ≥ 15
where x1= 13, and x2=2
13+12≥ 15
15≥ 15
At least 15 workers must be assigned to the shift 2.
The LP model questions require that the constraints are satisfied.
The constraint for the shift 2 is that the number of workers must be equal or greater than 15
This can be solved using other constraint functions e.g
Putting X4= 0 in
X1 + X4 ≥ 12
gives
X1 ≥ 12
Now Putting the value X1 ≥ 12 in shift 2 constraint
X1 + X2 ≥ 15
12+ 2≥ 15
14 ≥ 15
this does not satisfy the condition so this is wrong.
Now from
X2 + X3 ≥ 16
Putting X3= 14
X2 + 14 ≥ 16
gives
X2 ≥ 2
Putting these in the shift 2
X1 + X2 ≥ 15
13+2 ≥ 15
15 ≥ 15
Which gives the same result as above.
You would have no problem at all if it said "7 cows minus 2 cows", or "7 books minus 2 books". The THINGS just happen to be m's instead of cows or books.