A taxpayer engaged in service business provides you with the following: Description 2019 2020 Collections from services rendered-current P600,000 P800,000 Billings for revenues earned but uncollected 500,000 200,000 Collections from uncollected billings in 2019 470,000 Collections from uncollected billings in 2020 50,000 Advance collections for services not yet rendered 300,000 200,000\f