$194.17 is the present worth. $200 - $194.17 = $5.83 true discount.
The following rule can be deduced from the foregoing solution:—
Rule: 1. To find the present worth, divide the debt by the amount of $1 for the given time.
2. To find the true discount, subtract the present worth from the debt.
Case II.—Note bearing interest.
What is the present worth of a note of $300, bearing 6% interest, due in 2 years 4 months, if money is worth 10%.
Solution: Interest on $300 for 2 years 4 months at 6% = $42.
$300 + $42 = $342. Amount due at maturity.
Amount of $1 for 2 years 4 months at 10% = $1.231⁄3.
If $1.231⁄3 = amount of $1, then $3.42 is the amount of $3421.231⁄3, or $277.29.