How many odd integers between 2000 and 7000 have no repeated digits?

Question

 It is for my assignment

Answer 1

For 2000 to 2999

First digit, one choice - 2

Last digit, five choices - 1, 3, 5, 7, 9

Second digit, eight choices - anything except 2 and last digit

Third digit, seven choices - anything except 2, second digit, last digit

 

1(5)(8)(7) = 280

(5)(280) = 1400