Complete question :
At Alan's auto shop, it takes him 9 minutes to do an oil change and 12 minutes to do a tire change. Let x be the number of oil changes he does. Let y be the number of tire changes he does. Using the values and variables given, write an inequality describing how many oil changes and tire changes Alan can do in less than an hour ( minutes).
Answer:
9x + 12y < 120
Explanation:
Given that:
Time taken for oil change = 9 minutes
Time taken for tire change = 12 minutes
x = number of oil changes ; y = number of tire changes
Total hours = 1 hour = 60 minutes
Number of oil and Tyre changes possible in less than an hour
(Number of oil changes * time taken) + (number of tire changes * time taken) less than 60 minutes
9x + 12y < 120