LIVE Course for free

Rated by 1 million+ students
Get app now
0 votes
in Commercial Mathematics by (31.5k points)
closed by

A does 20% less work than B. If A can finish a piece of work in 7(1/2) hours then B can finish it in 

A. 5 hours

B. \(5\frac{1}{2}\) hours

C. 6 hours

D. \(6\frac{1}{2}\) hours

1 Answer

+1 vote
by (31.0k points)
selected by
Best answer

Number of hours taken by A to finish the work = \(7\frac{1}{2}\) hours = \(\frac{15}{2}\) hours

Work done by A in one hour : \(\frac{2}{15}\)

Let number of hours taken by B to finish the work : \(\frac{1}{x}\)

A can work 20% less than B that is \(\frac{20}{100}=\frac{4}{5}\) times of B’s work.

Here , \(\frac{4}{5}:1=\frac{2}{15}:\frac{1}{x}\)


x = \(\frac{15\,\times\,4}{5\,\times\,2}\) = 6 hours.

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.