Answer:
$1800
Step-by-step explanation:
First, rewrite out the information you already have:
-for 4 hrs-cost $850
-for 7 hrs-cost $1300
-for 12 hrs-$?
Next, we have to find out the amount of cost for hire per hour, so we can multiply that by 12 hrs:
-start by subtracting $850 from $1300:
1300-850=$450
-now subtract 4 hrs from 7 hrs:
7-4=3 hrs
In doing this, we see that the cost for 3 hrs hire is $450. Now, to find the unit cost per hr hire, divide $450 by 3 hrs:
450÷3=$150/hr
It costs $150 per hr hire.
Now, we have to find the cost for 12 hrs hire, so just multipy the unit cost by 12:
150*12=$1800 for 12 hrs hire
It costs $1800 for 12 hrs hire.