Mike wants to buy a new Dodge Charger. He is able to negotiate a price of $21,500 for the color and options he wanted. He can secure a 48 month car loan at 6.8% if he can make a down payment of 20% of the price.

a. How much are his car payments?

b. At the end of 20 months, Mike gets a bonus from work, and he decides to pay off his car loan. How much does he owe after 20 months?

For a I got $410.32 but I'm not sure if this is correct.

I plugged this information using this formulaP (1+r/n)^n*t = PMT [(1+r/n)^n*t-1]/(r/n)

I'm confused about question b though I know I need to use this formula U=P (1+r/n)^(n*T) - PMT [(1+r/n)^(n*T)-1]/(r/n)

I'm getting lost with what T should be, I was told it had to be in years and there is still 28 months left of the loan so should this be turned into a decimal or what?