Answer:
The correct option is;
B. s ≥ 12 - t, s ≤ 30 - t, s ≤ 24 - 0.66·t
Explanation:
The given parameters are;
The number of T-shirts, t, and shorts, s, Tim must design a day = 12
The maximum number of T-shirts and shorts Tim can design a day = 30
The maximum number of hours Tim can work = 18 hours
Therefore, we have;
The number of shorts Tim designs in a day is ≥ The minimum number of T-shirts and shorts Tim must design a day less the number of T-shirts Tim designs
Which gives;
s ≥ 12 - t
Also the number of shorts Tim designs in a day is ≤ The maximum number of T-shirts, and shorts, Tim can design a day less the number of T-shirts Tim designs
Which gives;
s ≤ 30 - t
The number of 45 minute period for the design of shorts in 18 hours = 18×60/45 = 24
The fraction of 36 minutes in 45 minutes = 36/45 = 0.667
Therefore we have;
The number of shorts Tim designs in a day is ≤ The number of 45 minute periods in 18 hours less the number of 36 minutes periods used to design T-shirts
Which gives;
s ≤ 24 - 0.66·t
The correct option is s ≥ 12 - t, s ≤ 30 - t, s ≤ 24 - 0.66·t.