Peppers Lockdown produces keys for homes and cars. As Peppers planned for next year’s production, the company decided to implement a high-low system to forecast future costs. With total production of 2,500,000 keys at a total cost of $10,000 in 2015, and total production of 3,000,000 keys at a total cost of $20,000 in 2016, what is the variable cost per key? (Round your answer to 2 decimal places.)

Hello I need assistance with the above question please? I thought $50 was the correct answer but it is not. It is very similiar to CLemson-MGT 2010 question 8-20