How many numbers with 2 different digits can be formed using only the odd digits? Answers
A) 10	B) 20	C) 40	D) 60	E) 120
Odd digits are 1, 3, 5, 7, 9.   We want 3 different digits.   First digit can be chosen in 5 ways.   Second digit can be chosen in 4 ways.   Total ways = 5*4= 
<gadget id="calculator">5*4</gadget>
<output>20</output>
20   Hence option (20).
<result>B</result>
How many numbers with 2 different digits can be formed using only the odd digits?