Working, independently X takes 10 hours to finish a certain work. He works for 9 hours. The rest of the work is finished by Y whose rate is 1/10 th of X. In how much time does Y finish his work?
Answers:
A) 2hrs
B) 4hrs
C) 6hrs
D) 8hrs
E) 10hrs
machine X will do 9/10 in 9 hrs, so X does 9/10 of the work ..   Therefore, Y will do the remaining 1/10 th work alone..   As the speed of Y is 1/10 rate of X, Y will do the 1/10 th work in same time that X takes to complete full job...   ans 10   10hrs
<result>E</result>
Working, independently X takes 10 hours to finish a certain work. He works for 9 hours. The rest of the work is finished by Y whose rate is 1/10 th of X. In how much time does Y finish his work?