U're goal is to get k alone.
So divide both sides by 9/10.
3/2 divided by 9/10 is 5/3
He will have a 1/531,441 chance of winning next week.
There are 10 balls in each container; for 6 containers, this gives us 10^6 = 1,000,000. There is 1 correct combination of balls, so his chance the first week is 1/1,000,000.
The second week, 1 ball is removed from each container; this will give us 9^6 = 531,441 chances. There is 1 correct combination, so he will have a 1/531,441 chance of winning.
558,739 is the correct answer.
