Allen, Birdy, and Carter are partners with capital balances of $100,000, $60,000 and $50,000 and who share in the profit and loss of the ABC partnership 40%, 10%, and 50%, respectively, when they agree to admit Derek for a 25% interest. If Derek contributes $40,000 to the partnership and the goodwill method is used, what amount would be Derek' capital balance after Derek joins?

$60,000 $50,000 $70,000 $62,000