What is the total cost to repay a $2 balance on a credit card loan with an apr of 18% and a minimum monthly payment of $310?

APR is 18%. We need to take the monthly interest which is equal to
= 18% / 12
= 1.5% (monthly interest)

Monthly, you have to pay
= (310 * 0.015) + 310
= $314.65

You need to repay the balance of $20,000.
Then multiplied it with APR of 18%
= (20, 000 * 0.18) + 20,000
= $23600.00