Sir or ma'am can you explain this question.
It is of accountancy.

Dear Student,
 

Machinery Account
Dr.						Cr.
Date	Particulars			Amount (Rs)	Date		Particulars		Amount (Rs)
2010					2010
Jan. 01	Bank A/c			40,000	Dec. 31		Depreciation A/c
July 01	Bank A/c (M2)			20,000			M1	4,000
							M2 (for 6 months)	1,000	5,000
					Dec. 31		Balance c/d
							M1	36,000
							M2	19,000	55,000
				60,000					60,000
2011					2011
Jan. 01	Balance b/d				Dec. 31		Depreciation A/c
	M1	36,000					M1	3,600
	M2	19,000		55,000			M2	1,900	5,500
					Dec. 31		Balance c/d
							M1	32,400
							M2	17,100	49,500
				55,000					55,000
2012					2012
Jan. 01	Balance b/d				July 01		Depreciation A/c (on M1 for 6 months)		1,620
	M1		32,400				Bank A/c (Sale of M1)		12,000
	M2		17,100	49,500			Profit and Loss A/c (Loss on Sale)		18,780
July 01	Bank A/c (M3)			64,000	Dec. 31		Depreciation on-
							M2	1,710
							M3 (for 6 months)	3,200	4,910
					Dec. 31		Balance c/d
							M2	15,390
							M3	60,800	76,190
				1,13,500					1,13,500

Loss on sale = Book value - Sale value
Book value = Cost as on Jan 01, 2012 - Depreciation for 6 months = 32,400 - 1,620 = Rs 30,780
Sale value (given) = Rs 12,000
Loss = Rs 18,780
Regards