LIVE Course for free

Rated by 1 million+ students
Get app now
JEE MAIN 2023
JEE MAIN 2023 TEST SERIES
NEET 2023 TEST SERIES
NEET 2023
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
0 votes
92 views
in Commercial Mathematics by (32.4k points)
closed by

A and B, working together can finish a piece of work in 6 days, while A alone can do it in 9 days. How much time will B alone take to finish it?

1 Answer

+1 vote
by (32.2k points)
selected by
 
Best answer

Number of days A required do a piece of work : 9 days 

Let number of days B required do a piece of work : X days 

Number of hours required by A and B together to do a piece of work : 6 days

Work done by A in one day: \(\frac{1}{9}\)

Work done by B in one day: \(\frac{1}{x}\)

Work done by A and B together in a day : \(\frac{1}{6}\)

Work done by A and B together in one day : \(\frac{1}{9}+\frac{1}{x}=\frac{x\,+\,9}{9x}=\frac{1}{6}\)

\(\therefore \frac{x\,+\,9}{9x}=\frac{1}{6}\)

⇒ 6X + 54 = 9X 

⇒ 3X = 54 

⇒ X = 54/3 = 18 

∴ B can do the work 18 days

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

Categories

...