How many four-digit numbers that do not contain the digits 2, 3, 4, 5, or 6 are there? Select:	A) 200	B) 400	C) 500	D) 600	E) 800
The 1st digit can be filled up by the numbers: {1,7,8,9} = 4 ways   The 2nd digit can be filled up by the numbers: {0,1,7,8,9} = 5 ways   The 3rd digit can be filled up by the numbers: {0,1,7,8,9} = 5 ways   The 4th digit can be filled up by the numbers: {0,1,7,8,9} = 5 ways   The total number of such four-digit numbers is   4*5*5*5= 
<gadget id="calculator">  4*5*5*5</gadget>
<output>500</output>
500   The answer is 500.
<result>C</result>
How many four-digit numbers that do not contain the digits 2, 3, 4, 5, or 6 are there?