uppose

$($i$)$ The continuously compounded risk$-$free interest rate for dollars is $4\%.$

$($ii$)$ The continuously compounded risk$-$free interest rate for pounds is $6\%.$

$($iii$)$ A one$-$year dollar$-$denominated European call option on pounds with strike price $1\mathrm{.}6$

costs $$0\mathrm{.}05.$

$($iv$)$ A one$-$year dollar$-$denominated European put option on pounds with strike price $1\mathrm{.}6$

costs $$0\mathrm{.}05.$

Determine the spot exchange rate of dollars per pound.

$2$