note 10 loan sales and securitizations loan sales we sell residential and commercial mortgage loans in loan securitization transactions sponsored by government national mortgage association ( gnma ) , fnma , and fhlmc and in certain instances to other third-party investors . gnma , fnma , and the fhlmc securitize our transferred loans into mortgage-backed securities for sale into the secondary market . generally , we do not retain any interest in the transferred loans other than mortgage servicing rights . refer to note 9 goodwill and other intangible assets for further discussion on our residential and commercial mortgage servicing rights assets . during 2009 , residential and commercial mortgage loans sold totaled $ 19.8 billion and $ 5.7 billion , respectively . during 2008 , commercial mortgage loans sold totaled $ 3.1 billion . there were no residential mortgage loans sales in 2008 as these activities were obtained through our acquisition of national city . our continuing involvement in these loan sales consists primarily of servicing and limited repurchase obligations for loan and servicer breaches in representations and warranties . generally , we hold a cleanup call repurchase option for loans sold with servicing retained to the other third-party investors . in certain circumstances as servicer , we advance principal and interest payments to the gses and other third-party investors and also may make collateral protection advances . our risk of loss in these servicing advances has historically been minimal . we maintain a liability for estimated losses on loans expected to be repurchased as a result of breaches in loan and servicer representations and warranties . we have also entered into recourse arrangements associated with commercial mortgage loans sold to fnma and fhlmc . refer to note 25 commitments and guarantees for further discussion on our repurchase liability and recourse arrangements . our maximum exposure to loss in our loan sale activities is limited to these repurchase and recourse obligations . in addition , for certain loans transferred in the gnma and fnma transactions , we hold an option to repurchase individual delinquent loans that meet certain criteria . without prior authorization from these gses , this option gives pnc the ability to repurchase the delinquent loan at par . under gaap , once we have the unilateral ability to repurchase the delinquent loan , effective control over the loan has been regained and we are required to recognize the loan and a corresponding repurchase liability on the balance sheet regardless of our intent to repurchase the loan . at december 31 , 2009 and december 31 , 2008 , the balance of our repurchase option asset and liability totaled $ 577 million and $ 476 million , respectively . securitizations in securitizations , loans are typically transferred to a qualifying special purpose entity ( qspe ) that is demonstrably distinct from the transferor to transfer the risk from our consolidated balance sheet . a qspe is a bankruptcy-remote trust allowed to perform only certain passive activities . in addition , these entities are self-liquidating and in certain instances are structured as real estate mortgage investment conduits ( remics ) for tax purposes . the qspes are generally financed by issuing certificates for various levels of senior and subordinated tranches . qspes are exempt from consolidation provided certain conditions are met . our securitization activities were primarily obtained through our acquisition of national city . credit card receivables , automobile , and residential mortgage loans were securitized through qspes sponsored by ncb . these qspes were financed primarily through the issuance and sale of beneficial interests to independent third parties and were not consolidated on our balance sheet at december 31 , 2009 or december 31 , 2008 . however , see note 1 accounting policies regarding accounting guidance that impacts the accounting for these qspes effective january 1 , 2010 . qualitative and quantitative information about the securitization qspes and our retained interests in these transactions follow . the following summarizes the assets and liabilities of the securitization qspes associated with securitization transactions that were outstanding at december 31 , 2009. .

Table:
in millions | december 31 2009 credit card | december 31 2009 mortgage | december 31 2009 credit card | mortgage
assets ( a ) | $ 2368 | $ 232 | $ 2129 | $ 319
liabilities | 1622 | 232 | 1824 | 319
( a ) represents period-end outstanding principal balances of loans transferred to the securitization qspes .
credit card loans at december 31 , 2009 , the credit card securitization series 2005-1 , 2006-1 , 2007-1 , and 2008-3 were outstanding .
during the fourth quarter of 2009 , the 2008-1 and 2008-2 credit card securitization series matured .
our continuing involvement in the securitized credit card receivables consists primarily of servicing and our holding of certain retained interests .
servicing fees earned approximate current market rates for servicing fees ; therefore , no servicing asset or liability is recognized .
we hold a clean-up call repurchase option to the extent a securitization series extends past its scheduled note principal payoff date .
to the extent this occurs , the clean-up call option is triggered when the principal balance of the asset- backed notes of any series reaches 5% ( 5 % ) of the initial principal balance of the asset-backed notes issued at the securitization .

Question: for how much more was the 2009 residential loan sold than the 2008 and 2009 commercial loans combined , in billions?
Answer: 10
Calculation: add(5.7, 3.1), subtract(19.8, #0)