Jane started baby-sitting when she was 18 years old. Whenever she baby-sat for a child, that child was no more than half her age at the time. Jane is currently 32 years old, and she stopped baby-sitting 12 years ago. What is the current age of the oldest person for whom Jane could have baby-sat? Choose the correct choice from the following options.
A) 20 B) 21 C) 22 D) 23 E) 24
Check two extreme cases:   Jane = 18, child = 9, years ago = 32-18= 
<gadget id="calculator">32-18</gadget>
<output>14</output>
14 --&gt; child's age now= 9+14= 
<gadget id="calculator">9+14</gadget>
<output>23</output>
23;   Jane= 20, child = 10, years ago = 32-20= 
<gadget id="calculator">32-20</gadget>
<output>12</output>
12 --&gt; child's age now= 10+12= 
<gadget id="calculator">10+12</gadget>
<output>22</output>
22.   Answer: 23.
<result>D</result>
Jane started baby-sitting when she was 18 years old. Whenever she baby-sat for a child, that child was no more than half her age at the time. Jane is currently 32 years old, and she stopped baby-sitting 12 years ago. What is the current age of the oldest person for whom Jane could have baby-sat?