An equipment costs Php $10,000$ with a salvage value of Php $500$ at the end of $10$ years. Calculate the total depreciation charge and book value at the end of

$7$ years using:

a$.$ straight line method

depreciation charge: Php$?$

book value: Php$?$

b$.$ sinking fund method at $4\%$ interest

depreciation charge: Php $?$

book value: Php $?$

c$.$ double declining balance method

depriciation charge: Php$?$

bool value: Php$?$