Inflation:
Inflation refers to the general increase in prices of goods and services in an economy over a period of time. It is often measured as the percentage change in the Consumer Price Index (CPI), which tracks the prices of a basket of commonly purchased goods and services. Inflation can have a significant impact on the purchasing power of consumers and the overall economy.

Interest Rate:
Interest rate is the cost of borrowing or the return on investment. It is the percentage charged or earned on a loan or an investment. Interest rates can be set by central banks or determined by market forces. They play a crucial role in influencing economic activity, as they affect the cost of borrowing, the return on savings, and the overall level of investment.

Equation Examples:
1. Inflation Rate Calculation:
The inflation rate can be calculated using the following formula:
Inflation Rate = ((CPI in Current Year - CPI in Previous Year) / CPI in Previous Year) * 100

For example, if the CPI in the current year is 120 and the CPI in the previous year is 100, the inflation rate would be:
((120 - 100) / 100) * 100 = 20%

2. Interest Rate Calculation:
The interest rate can be calculated using the following formula:
Interest Rate = (Interest / Principal) * 100

For example, if the interest on a loan is $500 and the principal amount is $10,000, the interest rate would be:
(500 / 10,000) * 100 = 5%

Solving for Inflation and Interest Rate:
To solve for inflation or interest rate, you would need the relevant data and apply the respective formulas mentioned above. Here are the steps for each:

Solving for Inflation Rate:
1. Obtain the CPI values for the current year and the previous year.
2. Subtract the CPI in the previous year from the CPI in the current year.
3. Divide the result by the CPI in the previous year.
4. Multiply the quotient by 100 to get the inflation rate.

Solving for Interest Rate:
1. Determine the interest amount and the principal amount.
2. Divide the interest by the principal.
3. Multiply the quotient by 100 to get the interest rate.

It is important to note that inflation and interest rates are dynamic and can fluctuate over time. They are influenced by various factors such as government policies, supply and demand dynamics, and market conditions. Monitoring and understanding changes in inflation and interest rates is essential for individuals, businesses, and policymakers to make informed financial decisions.