1. Isabel has two boxes of chocolates.  Box $A$ contains 4 caramels and 6 toffees, and box$B$ contains 5 caramels and $x$ toffees.  Isabel chooses a chocolate at random from box A and moves it to box B.  Her friend then takes a chocolate at random from box B. 

Show that the probability Isabel’s friend takes a caramel is given by $\frac{27}{5(x+6)}$.