(Concept Problem) A convertible bond is a bond that permits the holder to turn in the bond and convert it into a certain number of shares of stock. Conversion would, thus, occur only when the stock does well. As a result of the option to convert the bond to stock, the coupon rate on the bond is lower than it otherwise would be. A new type of financial instrument, the reverse convertible, pays a higher-than-normal coupon, but the principal payoff can be reduced if the stock falls. Let us specify that the principal payoff of the reverse convertible is $\mathrm{FV}$, the face value, if $S_{\mathrm{T}}>\mathrm{S}_0$ where $\mathrm{S}_0$ is the stock price when the bond is issued. If $\mathrm{S}_{\mathrm{T}} \leq \mathrm{S}_0$, the principal payoff is $\mathrm{FV}\left(\mathrm{S}_{\mathrm{T}} / \mathrm{S}_0\right)$. Thus, for example, if the stock falls by 10 percent, $\mathrm{S}_{\mathrm{T}} / \mathrm{S}_0$, the principal payoff, is $0.9 \mathrm{FV}$. Show that this payoff ( $\mathrm{FV}$ if $\mathrm{S}_T>\mathrm{S}_0$, and $\mathrm{FV}\left(\mathrm{S}_{\mathrm{T}} / \mathrm{S}_0\right)$ if $\left.\mathrm{S}_{\mathrm{T}} \leq \mathrm{S}_0\right)$ is equivalent to a combination of an ordinary bond and a certain number of European puts with an exercise price of $S_0$. Determine how many puts you would need.