Accounting Equation:

Assets = Liabilities + Owner's Equity

(a) Started business with Cash 2,00,000

Assets: Cash 2,00,000

(b) Purchased goods for cash 60,000 and on Credit 1,50,000

Assets:
- Cash 60,000
- Accounts Receivable 1,50,000

Liabilities: Accounts Payable 1,50,000

(c) Sold goods for cash costing 40,000 at a profit of 20% and on credit costing 72,000 at a profit of 25%

Assets:
- Cash 1,12,000 (40,000 + 72,000 x 0.75)
- Accounts Receivable 72,000

Liabilities: Accounts Payable 1,50,000

Owner's Equity:
- Sales Revenue 1,12,000
- Cost of Goods Sold (40,000 x 0.8) + (72,000 x 0.75 x 0.8) = 83,200
- Gross Profit 28,800

(d) Paid for rent 5,000

Assets:
- Cash 1,07,000 (1,12,000 - 5,000)

Liabilities: Accounts Payable 1,50,000

Owner's Equity:
- Rent Expense 5,000

Explanation:

The accounting equation is a fundamental principle in accounting that represents the relationship between a company's assets, liabilities, and owner's equity. It is used to keep track of a company's financial transactions and to prepare financial statements such as the balance sheet.

In this question, we have started a business with cash of 2,00,000. This cash is considered as an asset. We have then purchased goods for cash and on credit. The cash paid for purchases is also considered as an asset, and the amount payable to suppliers is considered as a liability.

Next, we have sold goods for cash and on credit, which has resulted in an increase in our cash and accounts receivable balances. The cost of goods sold is considered as an expense, and the sales revenue is considered as income. The difference between the two is gross profit.

Finally, we have paid for rent, which is an expense and has resulted in a decrease in our cash balance.

Overall, the accounting equation remains in balance, as the total assets are equal to the total liabilities and owner's equity.