How many numbers between 0 and 1570 have a prime tens digit and a prime units digit?
Choose one.
A) 268	B) 272	C) 202	D) 112	E) 252
From 1-9 there are 4 prime numbers {2, 3, 5, 7}. The 10s and 1s of the number must be made with these numbers. The total number of combinations is  4*4= 
<gadget id="calculator"> 4*4</gadget>
<output>16</output>
16. Thus every set of 100 consecutive positive integers has 16 such numbers.   From 0 to 1500, there  16*15= 
<gadget id="calculator"> 16*15</gadget>
<output>240</output>
240 such numbers.   From 1501 to 1570, the 10s units can only use 3 numbers {2, 3, 5}. 3*4=12.   The total number is then  240+12= 
<gadget id="calculator"> 240+12</gadget>
<output>252</output>
252   The answer is 252.
<result>E</result>
How many numbers between 0 and 1570 have a prime tens digit and a prime units digit?