A and B can do a piece of work in 40 days and 50 days respectively. They work together for 10 days and B leaves. In how many days the whole work is completed?  Choose the correct choice from the following choices
A) 28 days B) 60 days C) 20 days D) 30 days E) 40 days
Explanation:   (28 days+B)’s 10 days work = 10[1/40+1/50]=10[5+4/200]= 9/20   28 days complete remaining work in 9/20*40= 
<gadget id="calculator">9/20*40</gadget>
<output>18</output>
18   Total work= 10+18= 
<gadget id="calculator">10+18</gadget>
<output>28</output>
28days   28 daysnswer: Option 28 days
<result>A</result>
A and B can do a piece of work in 40 days and 50 days respectively. They work together for 10 days and B leaves. In how many days the whole work is completed?