interest rate in USA is $3\%,$ interest rate in UK is $4\%,$ spot rate in US e $=$ $$/$pound $=1\mathrm{.}22,$ and the forward rate f $=1\mathrm{.}20.$

a$.$ For an investor investing $$1000000,$ should she invest in US or UK$?$

b$.$ What will be the gain?