Code typo (6.2.7.2)

[kosgdk]

6.2.7.2 Do-It-Yourself

Some duplicated strings in code:

var mutable = 1
var mutable = 1 //Duplicate
mutable: Int = 1

mutable = 2
mutable = 2 //Duplicate
mutable: Int = 2

[davegurnell]

Looks like @daniashers fixed these when she moved our code to Tut. Thanks for the spot though!