How many numbers between 0 and 1770 have a prime tens digit and a prime units digit?  Choose the correct choice from the following options.
A) 266 B) 272 C) 278 D) 284 E) 290
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 1700, there  16*17= 
<gadget id="calculator"> 16*17</gadget>
<output>272</output>
272 such numbers.   From 1701 to 1770, the 10s units can only use 3 numbers {2, 3, 5}. 3*4=12.   The total number is then  272+12= 
<gadget id="calculator"> 272+12</gadget>
<output>284</output>
284   The answer is 284.
<result>D</result>
How many numbers between 0 and 1770 have a prime tens digit and a prime units digit?