A whale goes on a feeding frenzy that lasts for 9 hours. For the first hour he catches and eats x kilos of plankton. In every hour after the first, it consumes 3 kilos of plankton more than it consumed in the previous hour. If by the end of the frenzy the whale will have consumed a whopping accumulated total 360 kilos of plankton, how many kilos did he consume on the sixth hour?
Choose the correct option:
A) 38 B) 43 C) 50 D) 53 E) 62
If you list the amount eaten each hour, you'll get an equally spaced list, increasing by 3 each hour. In any equally spaced list, the median equals the mean. Here, the mean is  360/9= 
<gadget id="calculator"> 360/9</gadget>
<output>40</output>
40, so the median is also 40, and that is the amount eaten in the 5th hour. We need to add 3 to find the total eaten in the next hour, so the answer is 43.   option 43
<result>B</result>
A whale goes on a feeding frenzy that lasts for 9 hours. For the first hour he catches and eats x kilos of plankton. In every hour after the first, it consumes 3 kilos of plankton more than it consumed in the previous hour. If by the end of the frenzy the whale will have consumed a whopping accumulated total 360 kilos of plankton, how many kilos did he consume on the sixth hour?