Case of long $($buy$)$ euro put option:

Assume that K $=$ $$1\mathrm{.}10/$ and P $=$ $$0\mathrm{.}05/.$ One contact size is $12,500.$

a$.$ Show the payoff $($equation$/$function$)$ for buying one contract of this put option.

b$.$ Find the net profit for buying one contract when the sport rates at the exercise are $$1\mathrm{.}00/,$ $$1\mathrm{.}05/,$ $$1\mathrm{.}10/,$ & $$1\mathrm{.}15/.$