True Discount Questions
FACTS AND FORMULAE FOR TRUE DISCOUNT QUESTIONS
Suppose a man has to pay Rs.156 after 4 years and the rate of interest is 14% per annum. Clearly, Rs. 100 at 14% will amount to Rs. 156 in 4 years. So, the payment of Rs. 100 now will clear off the debt of Rs.156 due 4 years. Hence, we say that :
Sum due = Rs.156 due 4 years hence;
Present Worth (P.W) = Rs. 100;
True Discount (T.D) = (Sum due) - (P.W)=Rs. (156 - 100) = Rs. 56
We define :
T.D = Interest on P.W
Amount = (P.W) + (T.D)
Interest is reckoned on P.W and true discount is reckoned on the amount.
IMPORTANT FORMULAE
Let rate = R% per annum and Time = T years. Then,
1.
2.
3.
4. (S.I) - (T.D )= S.I on T.D
5. When the sum is put at compound interest, then