Answer:
$0.2456 / card in ink for printer B
Step-by-step explanation:
The formatting of the data tables isn't great in your question and it's hard to be sure of which numbers go where.
Since the question is about printer B, we'll assume the number of hours for printer B is 50 for week1, 50 for week2 and 3 for week3.
The numbers don't make much sense overall, but let's work with them.
We'll first calculate the ratio of hours worked by printer B with the overall hours all the printers worked, over the 3 weeks:
Printer A : 140 hours
Printer B : 130 hours
Printer C: 145 hours
Total 415 hours total, for the 3 printers.
Ratio of Printer B: 130 / 415 = 31.325%
Total of cards produced:
7,950 + 7,800 + 9,600 = 25,350 cards over 3 weeks.
We'll assume the productivity per hour is the same for all printers, since no indication otherwise. So, the portion of those 25K cards of printer B should be the same as the ratio of the hours worked:
25,340 * 31.325% = 7941 cards (rounded to the nearest unit)
Since we know printer B ran for 130 hours, and it costs $15/hour in ink, we have:
130 hours * 15$/hour = $1,950 in ink.
Now, we divide by the number of cards:
$1,950 / 7941 cards = $0.2456 / card in ink for printer B
