Allison Arkin sells homemade knit scarves for $25 each at local craft shows. Her contribution margin ratio is 60%. Currently, the craft show entrance fees cost Allison $900 per year. The craft shows are raising their entrance fees by 20% next year. How many extra scarves will Allison have to sell next year just to pay for rising entrance fee costs? Begin by identifying the general formula to compute the breakeven sales in units