What is the 4 digit number in which the 1st digit is 1/3 of the second, the 3rd is the sum of the 1st and 2nd, and the last is three times the second?  Select.
A) 1243
B) 1345
C) 1349
D) 1467
E) 1500
First digit is 1/3 second digit =&gt; The numbers can be 1 &amp; 3, 2&amp; 6, 3 &amp; 9.   First + second = third =&gt; we can eliminate 3 &amp; 9 since  3 + 9= 
<gadget id="calculator"> 3 + 9</gadget>
<output>12</output>
12.   Last is 3 times the second=&gt; we can eliminate option 2 &amp; 6 since  3 * 6= 
<gadget id="calculator"> 3 * 6</gadget>
<output>18</output>
18.   Hence the number is 1349   1349
<result>C</result>
What is the 4 digit number in which the 1st digit is 1/3 of the second, the 3rd is the sum of the 1st and 2nd, and the last is three times the second?