In 2018, Alalay received from Bataan a promissory note with a face value of P100,000 for services rendered by the former to the latter. The note will mature in 2019. At the time of receipt in 2018, the note may be sold to a bank at a discount of 18%. Bataan paid the note upon maturity in 2019. Required: Discuss how much is the income subject to tax each year.