A and B can do a piece of work in 10 days and 10 days respectively. They work together for 10 days and B leaves. In how many days the whole work is completed? Choose the correct answer:
A) 30days B) 40days C) 50days D) 60days E) 70days
Explanation:   (30days+B)’s 10 days work = 10[1/10+1/10]=10[1+1/10]= 2   30days complete remaining work in   2*10= 
<gadget id="calculator">  2*10</gadget>
<output>20</output>
20   Total work= 10+20= 
<gadget id="calculator">10+20</gadget>
<output>30</output>
30days   30daysnswer: Option 30days
<result>A</result>
A and B can do a piece of work in 10 days and 10 days respectively. They work together for 10 days and B leaves. In how many days the whole work is completed?