How many integers between 5000 and 6000 that have distinct digits and increase from left to right ?  Choose the correct choice from the following choices
A) 10	B) 48	C) 60	D) 20	E) 600
Since the numbers must be distinct and increasing from left to right,   The only arrangements we could come-up with are:   545_ --&gt; 4   546_ --&gt; 3   547_ --&gt; 2   548_ --&gt; 1   556_ --&gt; 3   557_ --&gt; 2   558_ --&gt; 1   567_ --&gt; 2   568_ --&gt; 1   578_ --&gt; 1   Number of integers =20   20
<result>D</result>
How many integers between 5000 and 6000 that have distinct digits and increase from left to right ?