Multiple choice

Kamal invested Rs.2400 and Rs.3000, one at the rate of 10% SI per annum and another at x% SI per annum respectively. If he interchanges the rate of interest he got Rs.120 more at the end of two years, and then find the value of x

  1. 12%

  2. 24%

  3. 20%

  4. 10%

  5. 30%
Reveal answer Fill a bubble to check yourself
C Correct answer
AI explanation

Let the two principals be P1 equal to 2400 and P2 equal to 3000, with respective simple interest rates of 10% and x%. Using the formula for the difference when interchanging rates, (P2 minus P1) times (R2 minus R1) times time divided by 100 equals the difference in interest. Substituting the values gives 600 times x minus 10 times 2 divided by 100 equals 120. Solving this, 12 times x minus 10 equals 120, so x minus 10 equals 10, making the value of x 20%.

Keep practicing — related questions