Discussion
The true discount on a certain sum due 3 years hence at 10% per annum is ₹150. What is the sum due?
Answer: B
Correct answer: ₹650
The true discount relates to the face value by \[ \text{TD} = \frac{A \times RT}{100 + RT}. \] Here \( RT = 10 \times 3 = 30 \), so \[ 150 = \frac{A \times 30}{130} \;\Rightarrow\; A = \frac{150 \times 130}{30} = 650. \] Checking: the present worth is \( 650 - 150 = 500 \), and the simple interest on 500 at 10% for 3 years is \( 500 \times 0.30 = 150 \), which is the true discount as given. The distractor 600 is what comes of treating the discount as interest on the face value - \( 150 \times 100/30 = 500 \) would then be the sum, and 600 is a near miss on the same reasoning. The formula worth carrying is that the present worth is always \( \dfrac{100A}{100+RT} \), and the true discount is what is left of \( A \) after subtracting it.
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development