How many integerskgreater than 100 and less than 700 are there such that if the hundreds and the units digits ofkare reversed, the resulting integer is k+99?
Choose the correct answer
A) 50  B) 60  C) 70  D) 80  E) 90
Numbers will be like 102 =&gt; 201 = 102 + 99   203 =&gt; 302 = 103 + 99   so the hundereth digit and units digit are consecutive where unit digit is bigger than hundred digit.   There will be five pairs of such numbers   for every pair there will 10 numbers like for 12 =&gt; 102, 112,132,142,152, 162,172,182,192.   Total = 5 *10= 
<gadget id="calculator">5 *10</gadget>
<output>50</output>
50 hence 50.
<result>A</result>
How many integerskgreater than 100 and less than 700 are there such that if the hundreds and the units digits ofkare reversed, the resulting integer is k+99?