Answer:
The cost for a repair that takes one and a half hour is £52
Step-by-step explanation:
We can create a function that relates the value Wayne charges in function of the time it takes for him to fix the washing machine in hours. Since there's a fixed cost of 28 and another charge that is variable of 16 per half hour, then the function below represents the cost of the repair:
[tex]cost(t) = 28 + 32*t[/tex]
In this case the variable value "16" was multiplied by two, because it's easier when the time is given in hours and every hour contains two half-hours. If the repair took 1.5 h, then:
[tex]cost(1.5) = 28 + 16*1.5\\cost(1.5) = 52\\[/tex]
The cost for a repair that takes one and a half hour is £52
