Question

How many numbers between 5000 and10000can be formed using the digits 1,2,3,4,5,6,7,8,9 each digit appearing not more than once in each number?

Answer 1

123456789
134567892
145678923
156789234
167892345
178923456
189234567
192345678


213456789
234567891
245678913
256789134
267891345
278913456
289134567
291345678

345678912
356789124
367891245
378912456
389124567
391245678
312456789
324567891


456789123
467891235
478912356
489123567
491235678
412356789
423567891
435678912

567891234
578912346
589123467
591234678
512346789
523467891
534678912
546789123

678912345
689123457
691234578
612345789
623457891
634578912
645789123
657891234

789123456
791234568
712345689
723456891
734568912
745689123
756891234
768912345


891234567
812345679
823456791
834567912
845679123
856791234
867912345


912345678
923456781
934567812
945678123
956781234
967812345
978123456
981234567