Break down this math problem: Helen cuts her lawn starting in March and finishes in October.  Her lawn mower uses 2 gallons of gas every 4th time she cuts her lawn.  For March, April, September and October, she only cuts her law 2 times per month.  In May, June, July and August, she has to cut her lawn 4 times per month.  How many gallons of gas will she need to cut her lawn from March through October?