Jane started baby-sitting when she was 20 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 10 years ago. What is the current age of the oldest person for whom Jane could have baby-sat? Select.
A) 20
B) 21
C) 22
D) 23
E) 24
Check two extreme cases:   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;   Jane= 22, child = 11, years ago = 32-22= 
<gadget id="calculator">32-22</gadget>
<output>10</output>
10 --&gt; child's age now= 11+10= 
<gadget id="calculator">11+10</gadget>
<output>21</output>
21.   Answer: 22.
<result>C</result>
Jane started baby-sitting when she was 20 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 10 years ago. What is the current age of the oldest person for whom Jane could have baby-sat?