Reena took a loan of Rs. 1200 with simple interest for as many years as the…

2023

Reena took a loan of Rs. 1200 with simple interest for as many years as the rate of interest. If she paid Rs. 432 as interest at the end of the loan period, what was the rate of interest?

  1. A.

    5

  2. B.

    6

  3. C.

    66.5

  4. D.

    6.5

Attempted by 9 students.

Show answer & explanation

Correct answer: B

Step-by-Step Solution

To find the rate of interest when the time period in years is numerically equal to the rate percentage, we use the standard simple interest formula.

  1. Define the variables based on the problem:

    • Principal (P) = Rs. 1200

    • Simple Interest (S.I.) = Rs. 432

    • Let the Rate of interest be R%.

    • According to the problem, the Time (T) = R years.

  2. Apply the simple interest formula:

    • S.I. = (P * R * T) / 100

    • Substitute the known values: 432 = (1200 * R * R) / 100

  3. Solve for R:

    • Simplify the equation: 432 = 12 * R^2

    • Divide both sides by 12: R^2 = 432 / 12

    • R^2 = 36

    • Take the square root of both sides: R = 6

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