A and B can do a piece of work in 6 days, B and C in 7 days, C and A in 8 days. How long will C take to do it?	Options
A) 12.6 days  B) 14.4 days  C) 15.2 days  D) 16.8 days  E) 18.2 days
2c = 1/7 + 1/8 – 1/6 = 20/168 = 10/84   c = 5/84 =&gt; 84/5= 
<gadget id="calculator">84/5</gadget>
<output>84/5 = around 16.8</output>
16.8 days   The answer is 16.8 days.
<result>D</result>
A and B can do a piece of work in 6 days, B and C in 7 days, C and A in 8 days. How long will C take to do it?