P, L, and O are partners with capital balances of $50,000, $30,000 and $20,000 and who share in the profit and loss of the PLO partnership 30%, 20%, and 50%, respectively, when they agree to admit C for a 20% interest.

If C contributes $40,000 to the partnership and the goodwill method is used, what amount will be debited for goodwill? A. $15,000 B. $20,000 C. $25,000 D. $28,000 E. $60,000

I need detailed calculations as to why answer is E)