For March, April, September and October, she cuts her lawn 2 a month. There are 4 months so she cuts her yard 2*4 = <<2*4=8>>8 times
For May, June, July and August, she cuts her lawn 4 times a month. There are 4 months so she cuts her yard 4*4 = <<4*4=16>>16 times
During the entire 8 month period, she cuts her lawn 8+16 = <<8+16=24>>24 times
Every 4th time she cuts, she needs 2 gallons of gas. If she cuts her lawn 24 times a year then she needs to fill up 24/4 = 6 times
Each time she fills up, it takes 2 gallons of gas so 2*6 = <<2*6=12>>12 gallons of gas per year
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