The four digits 6 7 8 and 9 can be arranged to form 24 different four digit numbers if these numbers are arranged from smallest to largest which number is in the seventeeth position?

Answer 1

First off, there are 6 arrangements that begin with 6, 6 that begin with 7, 6 that begin with 8, and 6 that begin with 9. This means the number begins with 8, since the number 8 begins all of the integers from positions 13 to 18. That gives you:

8 _ _ _

You do the same thing again, where 6 has the first two, 7 the middle two, and 9 the last two combinations, or those in position 17 and 18. We are now at

89 _ _

6 is the first one and 7 is the second out of the two numbers in positions 17 and 18, so the answer must be:

8967.

Answer 2

F