A completes a work in 15 days and B complete the same work in 30 days. If both of them work together, then the number of days required to complete the work will be  Choose one.
A) 8 days	B) 9 days	C) 10 days	D) 12 days	E) 13 days
If A can complete a work in x days and B can complete the same work in y days, then, both   of them together can complete the work in x y/ x+ y days   Therefore, here, the required number of days = 15 ×30/ 45 = 10 days.   Answer : 10 days
<result>C</result>
A completes a work in 15 days and B complete the same work in 30 days. If both of them work together, then the number of days required to complete the work will be