How many 4-digit numerals begin with a digit that represents a prime and end with a digit that represents a prime number?	Answers.
A) 1600
B) 80
C) 160
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   3rd place can be filled in 4 ways   Total=4*10*10*4= 
<gadget id="calculator">4*10*10*4</gadget>
<output>1_600</output>
1600   1600ns : 1600
<result>A</result>
How many 4-digit numerals begin with a digit that represents a prime and end with a digit that represents a prime number?