Tough one - Less than 10000

rashminet84 you are a genius. Not sure what are you doing here....go give ur GMAT...

Really??

Thanks for your kind words. though i am pretty weak in a lot of areas. I just learnt a few concepts while preparing for the Indian GMAT - Common Admission Test.

So kinda bored at work. And decided to visit the old forums. This one was not too dif.

My approach is not as good or quick as rashmine, but it works.

Ignore all numbers above 5001.

For 1000's Digit We have

5000 nothing above this will work.

4001, nothing above this combo works. Ignore the 4 and we have 3!/2!. Why because 001, 100, 010

3002, Again 3!/2!

3011, again 3!/2!

2003, 3!/2!

2012, 3!/2!

2102, 3!/2!

2201, 3!/2

1013, 3! --> 013 has six combinations

1022, 3!/2!

1121, 3!/2!

1004, 3!/2!

Now to 100's

500,

401, 3!

320, not 3! b/c 0 cannot be in hundreds digit.

113, 3!/2!

10's digit:

50, 41, 14, 32, 23

1's - 5.


Achieved in 4min, so I would def. reccomend Rashmine's approach.