Step-by-step explanation:

To calculate the percentage increase over two years, we need to use the simple interest formula:

Simple interest (SI) = (P * R * T) / 100

Where,

P = Principal amount

R = Rate of interest

T = Time in years

Let's assume the principal amount is 100, then the interest earned in the first year at 10% rate would be:

SI1 = (100 * 10 * 1) / 100 = 10

So, the amount at the end of the first year would be 100 + 10 = 110.

Now, for the second year, the interest earned at a 12% rate would be:

SI2 = (110 * 12 * 1) / 100 = 13.2

So, the amount at the end of the second year would be 110 + 13.2 = 123.2

Therefore, the percentage increase over two years would be:

((Final amount - Initial amount) / Initial amount) * 100

= ((123.2 - 100) / 100) * 100

= 23.2%

So, the percentage increase during these two years is 23.2%.

Answer:

The total percentage increase in the 2 years is 23.2%

Step-by-step explanation:

Given:

• Rates of interest for two consecutive years are 10% and 12% respectively.

To Find:

The percentage increase during these two years.

Calculation:

Let, the principal is = y

Simple Interest formula = Principal x Time in years x Interest rate in Percentage / 100

Amount = Principal + Interest

In the first year the rate of interest is 10%

So, the interest of the first year is = y x 10/100 = 0.1y

After first year the principal is now = y + 0.1y = 1.1y

In the second year the interest is = 1.1y x 12/100 = 0.132y

Now the amount is = 1.1y + 0.132y = 1.232 y

Percentage increase = 1.232y - y / y x 100 % = 23.2%

Hence, The total percentage increase in the 2 years is 23.2%. ( ans. )