A work as fast as B. If B can complete a work in 20days independently,the number of days in which A and B can together finish the work in?
Choose the most appropriate option.
A) 2days  B) 3days  C) 4days  D) 5days  E) 6 2/3days
Ratio of rates of working of A and B = 2:1   ratio of times taken = 1:2   A's 1day work = 1/10   B's 1day work = 1/20   A+B 1day work = 1/10 + 1/20  +  1= 
<gadget id="calculator"> +  1</gadget>
<output>1</output>
1/10 + 1/20= 3/20 =&gt; 20/3 = 6 2/3   A and B can finish the work in 6 2/3days   Answer is 6 2/3days
<result>E</result>
A work as fast as B. If B can complete a work in 20days independently,the number of days in which A and B can together finish the work in?