How many 3-digit numerals begin with a digit that represents a prime number?  Choose one
A) 16	B) 80	C) 400	D) 180	E) 240
prime digits 2,3,5 and 7.   three digit numbers _ _ _   1st place can be filled in 4 ways   2nd place can be filled in 10 ways   3rd place can be filled in 10 ways   Total=4*10*10= 
<gadget id="calculator">4*10*10</gadget>
<output>400</output>
400   Ans : 400
<result>C</result>
How many 3-digit numerals begin with a digit that represents a prime number?