Mr. Roper cuts his lawn 15 days a month beginning in April and ending in September.  From October to the end of March he cuts his lawn three times a month.  What is the average number of times that Mr. Roper cuts his yard per month?
For 6 months of the year he cuts his yard 15 days per month so he cuts his yard 6*15 = 
<gadget id="calculator">6*15</gadget>
<output>90</output>
90 times.
For the remaining 6 months of the year, he cuts his yard three times a month so he cuts his yard 6*3 = 
<gadget id="calculator">6*3</gadget>
<output>18</output>
18 times.
He cuts his yard 90 times for part of the year and 18 times for the rest of the year for a total of 90+18 = 
<gadget id="calculator">90+18</gadget>
<output>108</output>
108 times.
There are 12 months in a year and he cuts his yard 108 times so he averages 108/12 = 
<gadget id="calculator">108/12</gadget>
<output>9</output>
9 times per month.

<result>9</result>