On a ferry, there are 32 cars and 8 trucks. The cars have an average mass of 900 kg and the trucks have an average mass of 3000 kg. What is the average mass of all 40 vehicles on the ferry?	Answers
A) 1200 B) 1240 C) 1280 D) 1320 E) 1360
The total mass of the vehicles is 32*900+8*3000= 
<gadget id="calculator">32*900+8*3000</gadget>
<output>52_800</output>
52800   The average mass is   52800/40= 
<gadget id="calculator">  52800/40</gadget>
<output>1_320</output>
1320   The answer is 1320.
<result>D</result>
On a ferry, there are 32 cars and 8 trucks. The cars have an average mass of 900 kg and the trucks have an average mass of 3000 kg. What is the average mass of all 40 vehicles on the ferry?