A purchased a computer on 1-4-06 for
Rs.60,000 and another on 1-10-07 for Rs.
40, 000. He charged depreciation @ 20% p.a
Under straight line method. What will be the
Balance as on 31-03-09

For the first item purchased on Jan 4, 2006 you have to calculate 3 years and 3 months of depreciation. The yearly rate will be the cost of 60,000 * 20% * 3. For the 3 months you need to take the 60,000 * 20% * 3/12.

For the other item you need to calculate for 2 years and 3 months.
So: 40,000 * 20% * 2 and 40,000 * 20% * 2/12.

Then add your amounts together, which is your Accumulated Depreciation account balance.