XXX can do piece of work in 30 days while YYY alone can do it in 40 days. In how many days can XXX and YYY working together do it?
Choose the correct answer
A) 17 1/7
B) 15 1/7
C) 20 1/7
D) 22 1/7
E) 13 1/7
XXX one day worl = 1/30   YYY one day work = 1/40   (xxx + yyy) one day work = 1/30+1/40   ==&gt;7/20   No of days req for XXX and YYY to finish the work = 1/7/120 = 17 1/7 days   17 1/7NSWER 17 1/7
<result>A</result>
XXX can do piece of work in 30 days while YYY alone can do it in 40 days. In how many days can XXX and YYY working together do it?