John can complete a given task in 20 days. Jane will take only 12 days to complete the same task. John and Jane set out to complete the task by beginning to work together. However, Jane was indisposed 4 days before the work got over. In how many days did the work get over from the time John and Jane started to work on it together?  Select the correct option:  A) 6  B) 10  C) 8  D) 7.5  E) 3.5
John 6*20= 
<gadget id="calculator">6*20</gadget>
<output>120</output>
120   Jane   10*12= 
<gadget id="calculator">  10*12</gadget>
<output>120</output>
120   In 4 days working alone John did: 4 Days * Rate= 4*6= 
<gadget id="calculator">4*6</gadget>
<output>24</output>
24, so working together they did 120-24= 
<gadget id="calculator">120-24</gadget>
<output>96</output>
96 --&gt; Rate(A+B)*t=96 -&gt; 16*t=96, t=6. hence the answer is 10 (John worked 4 days + 6 days they worked together = 10 days)
<result>B</result>
John can complete a given task in 20 days. Jane will take only 12 days to complete the same task. John and Jane set out to complete the task by beginning to work together. However, Jane was indisposed 4 days before the work got over. In how many days did the work get over from the time John and Jane started to work on it together?