The cost per liter of petrol during a 4 year period is as follows:
Year 1, $1 per liter ;
Year 2, $1.5 per liter ;
Year 3, $1.2 per liter ;
Year 4, $2 per liter .
If a factory spent equal dollars on petrol each year, what was the average cost of a liter of petrol during the 4 year period?
Choose the correct choice from the following choices.
A) $1.22  B) $1.333  C) $1.425  D) $1.175  E) $1.500
Let money spent each year = $6   liters bought first year = 6   liters bought second year = 4   liters bought third year = 5   liters bought fourth year = 3   Total number of liters = 18   Total money spent = 6*4= 
<gadget id="calculator">6*4</gadget>
<output>24</output>
24   Average= 24/18 = 4/3 = 1.33   Answer is $1.333
<result>B</result>
The cost per liter of petrol during a 4 year period is as follows:
Year 1, $1 per liter ;
Year 2, $1.5 per liter ;
Year 3, $1.2 per liter ;
Year 4, $2 per liter .
If a factory spent equal dollars on petrol each year, what was the average cost of a liter of petrol during the 4 year period?