2.Business purchased motor car on 1July fo 20000. It is depreciated 20% on straight line basis. Assuming residuel value at the end of 5 years of 4000 with proportionate depreciation charge in the year of purchase. 20000 cost was correctly entered in the cash book but posted to debit of motor vehicles repairs account. I’ve checked the answer of this exercise The depreciation understated: ((20000-4000)*20%*6/12)=1600 But why we need to deducted its residuel(4000)