Explanation:

- To understand the problem, let's first determine the rate of interest.

- The money becomes 4 times its original value in 12 years.

- This means the interest is 3 times the original sum in 12 years (since simple interest is calculated as original sum x rate x time).

- Let the original amount be P. Then the total after 12 years is 4P, so interest earned is 3P.

- The formula for simple interest is Interest = Principal x Rate x Time.

- Therefore, 3P = P x R x 12, which simplifies to R = 1/4 per year.

Now, let's find when it becomes 10 times the original sum.

- Total amount = 10P, so interest earned is 9P.

- Using the formula again: 9P = P x (1/4) x Time.

- Simplifying, Time = 36 years.

- Option 4: 36 years is correct.

- Thus, the money will become 10 times in 36 years at the same rate.

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