on 1.1.90 there was machinery worth rs. 1,80,000 in a business firm. on 30.6.1990 machine was purchased for rs. 20,000. on 31.12.1990, a machine was sold for rs. 4,200 which was purchased for rs. 4,000 on 1.1.90. - on 31.12.91, a machine which was purchased on 1.1.90 for rs. 12,000 was sold or rs. 8,000. depreciation is provided at 10% per annum on fixed instalment basis. assuming provision for depreciation a/c is not maintained, prepare machinery alc for o and 1991.