Journal Entries:

1. Jan 1: Started business with a capital of ₹80,000.

Journal Entry:
```
Cash A/C Dr. ₹80,000
To Capital A/C ₹80,000
(Being capital introduced in the business)
```

2. Purchased goods for ₹21,000.

Journal Entry:
```
Purchases A/C Dr. ₹21,000
To Cash A/C ₹21,000
(Being goods purchased)
```

3. Bought furniture for ₹20,000.

Journal Entry:
```
Furniture A/C Dr. ₹20,000
To Cash A/C ₹20,000
(Being furniture purchased)
```

5. Sold goods for ₹18,000.

Journal Entry:
```
Cash A/C Dr. ₹18,000
To Sales A/C ₹18,000
(Being goods sold for cash)
```

6. Sold goods to Mr. K on credit for ₹15,000.

Journal Entry:
```
Mr. K A/C Dr. ₹15,000
To Sales A/C ₹15,000
(Being goods sold on credit to Mr. K)
```

8. Purchased goods from Mr. D on credit for ₹6,000.

Journal Entry:
```
Purchases A/C Dr. ₹6,000
To Mr. D A/C ₹6,000
(Being goods purchased on credit from Mr. D)
```

16. Cash received from Mr. I ₹14,950. Allowed him a discount of ₹50.

Journal Entry:
```
Cash A/C Dr. ₹14,950
Discount Allowed A/C Dr. ₹50
To Mr. I A/C ₹15,000
(Being cash received from Mr. I and discount allowed)
```

18. Paid cash to Mr. D ₹2,000.

Journal Entry:
```
Mr. D A/C Dr. ₹2,000
To Cash A/C ₹2,000
(Being cash paid to Mr. D)
```

22. Drawings for personal use ₹2,000.

Journal Entry:
```
Drawings A/C Dr. ₹2,000
To Cash A/C ₹2,000
(Being cash withdrawn for personal use)
```

25. Opened a bank account by depositing ₹11,000.

Journal Entry:
```
Bank A/C Dr. ₹11,000
To Cash A/C ₹11,000
(Being amount deposited in the bank)
```

26. Cash sales ₹5,000.

Journal Entry:
```
Cash A/C Dr. ₹5,000
To Sales A/C ₹5,000
(Being cash sales)
```

31. Rent paid ₹2,000.

Journal Entry:
```
Rent A/C Dr. ₹2,000
To Cash A/C ₹2,000
(Being rent paid)
```

31. Salary paid ₹3,500.

Journal Entry:
```
Salary A/C Dr. ₹3,500
To Cash A/C ₹3,500
(Being salary paid)
```



Answer :

Let's create the journal entries for Mr. R's business transactions in January 2019 step-by-step:

1. Jan 1: Mr. R commences his business with a capital of ₹ 80,000.
- Debit: Cash ₹ 80,000
- Credit: Capital Account ₹ 80,000

2. Jan 2: Purchased goods for ₹ 21,000.
- Debit: Purchase Account ₹ 21,000
- Credit: Cash ₹ 21,000

3. Jan 3: Bought Aunitwe for ₹ 20,000.
- Debit: Furniture Account ₹ 20,000
- Credit: Cash ₹ 20,000

4. Jan 5: Sold goods for ₹ 18,000.
- Debit: Cash ₹ 18,000
- Credit: Sales Account ₹ 18,000

5. Jan 16: Sold goods to Mr. K on credit for ₹ 15,000.
- Debit: Debtors (Mr. K) ₹ 15,000
- Credit: Sales Account ₹ 15,000

6. Jan 8: Purchased goods from Mr. D on credit ₹ 6,000.
- Debit: Purchase Account ₹ 6,000
- Credit: Creditors (Mr. D) ₹ 6,000

7. Jan 15: Cash received from Mri ₹ 14,950 and allowed a discount of ₹ 50.
- Debit: Cash ₹ 14,950
- Debit: Discount Allowed ₹ 50
- Credit: Debtors (Mri) ₹ 15,000

8. Jan 18: Paid cash to Mr. D ₹ 2,000.
- Debit: Creditors (Mr. D) ₹ 2,000
- Credit: Cash ₹ 2,000

9. Jan 22: Drawing for personal use ₹ 2,000.
- Debit: Drawing Account ₹ 2,000
- Credit: Cash ₹ 2,000

10. Jan 25: Opened a bank account by depositing ₹ 11,000.
- Debit: Bank Account ₹ 11,000
- Credit: Cash ₹ 11,000

11. Jan 26: Cash sales ₹ 5,000.
- Debit: Cash ₹ 5,000
- Credit: Sales Account ₹ 5,000

12. Jan 31: Rent paid ₹ 2,000.
- Debit: Rent Account ₹ 2,000
- Credit: Cash ₹ 2,000

13. Jan 31: Salary paid ₹ 3,500.
- Debit: Salary Account ₹ 3,500
- Credit: Cash ₹ 3,500

In summary, the journal entries for the given transactions are:

| Date | Particulars | Debit (₹) | Credit (₹) |
|----------|------------------------|-----------|------------|
| Jan 1 | Cash | 80,000 | |
| | Capital Account | | 80,000 |
| Jan 2 | Purchase Account | 21,000 | |
| | Cash | | 21,000 |
| Jan 3 | Furniture Account | 20,000 | |
| | Cash | | 20,000 |
| Jan 5 | Cash | 18,000 | |
| | Sales Account | | 18,000 |
| Jan 8 | Purchase Account | 6,000 | |
| | Creditors (Mr. D) | | 6,000 |
| Jan 15 | Cash | 14,950 | |
| | Discount Allowed | 50 | |
| | Debtors (Mri) | | 15,000 |
| Jan 16 | Debtors (Mr. K) | 15,000 | |
| | Sales Account | | 15,000 |
| Jan 18 | Creditors (Mr. D) | 2,000 | |
| | Cash | | 2,000 |
| Jan 22 | Drawing Account | 2,000 | |
| | Cash | | 2,000 |
| Jan 25 | Bank Account | 11,000 | |
| | Cash | | 11,000 |
| Jan 26 | Cash | 5,000 | |
| | Sales Account | | 5,000 |
| Jan 31 | Rent Account | 2,000 | |
| | Cash | | 2,000 |
| Jan 31 | Salary Account | 3,500 | |
| | Cash | | 3,500 |

These entries will be recorded in the journal to reflect the financial transactions that took place in the business during the month of January.