Unsuited cards

Question 1

When playing two unsuited cards what are the odds/probability of flopping a flush draw?

Answer 1

88 to 1
or
1.12%

Question 2

When playing two unsuited cards what are the odds/probability of flopping a back door flush draw?

Answer 2

6.8 to 1
or
12.8%

Question 3

When playing two unsuited cards what are the odds/probability of making a flush by the river?

Answer 3

53 to 1
or
1.85%