Journal Entries:

1. On 1st April 2008:
Machine A/C Dr. 50,000
To Cash/Bank A/C 50,000

Explanation:
The machine is purchased for Rs 50,000, so the machine account is debited to record the increase in assets. The corresponding entry is made in the cash/bank account to record the decrease in cash/bank balance.

Depreciation Calculation:

Depreciation is calculated at a rate of 10% p.a. using the fixed installment method. Under this method, the depreciation amount is the same every year.

Depreciation Amount = (Cost of Machine - Scrap Value) / Useful Life

Given:
Cost of Machine = Rs 50,000
Rate of Depreciation = 10% p.a.

Since the scrap value is not given, we assume it to be zero.

Depreciation Amount = (50,000 - 0) / 3 years = Rs 16,667

Machine Account:

| Date | Particulars | Debit (Rs) | Credit (Rs) |
|------------|----------------------------|------------|-------------|
| 01-04-2008 | To Cash/Bank A/C | 50,000 | |
| 31-03-2009 | By Depreciation A/C | 16,667 | |
| 31-03-2010 | By Depreciation A/C | 16,667 | |
| 31-03-2011 | By Depreciation A/C | 16,666 | |
| | Total | 100,000 | |
| | Balance c/d | | 50,000 |
|------------|----------------------------|------------|-------------|
| | Total | 100,000 | 100,000 |
|------------|----------------------------|------------|-------------|

Explanation:
The machine account is prepared for 3 years, considering the depreciation charged under the fixed installment method. The depreciation amount of Rs 16,667 is credited every year in the machine account to record the decrease in its value.

The balance carried down (c/d) at the end of the third year is Rs 50,000, which represents the remaining value of the machine after three years of depreciation.

Conclusion:
By following the rules and calculations mentioned above, the journal entries for the purchase of the machine and the preparation of the machine account for 3 years can be accurately recorded and presented.

depreciation RS 5000 each year, balance of machinery a/c in third year RS 35,000