Quantitative Aptitude – Arithmetic – Time and Work – When they work alone, B needs 25%

Slot -1 – Quantitative Aptitude – Arithmetic – Time and Work – When they work alone, B needs 25%

When they work alone, B needs 25% more time to finish a job than A does. They two finish the job in 13 days in the following manner: A works alone till half the job is done, then A and B work together for four days, and finally B works alone to complete the remaining 5% of the job. In how many days can B alone finish the entire job?

a) 22

b) 18

c) 20

d) 16

Solution:

ratio of time taken by A and B to complete the work alone = 1: 1.25 = 4x : 5x

As A complete half of the work alone  and B complete 5% of the work alone, so they will complete remaining 45% of work in 4 days .

So time taken by them to complete the whole work together = 4 * 100/45 = 80/9

Or (4x*5x)/(4x+5x) = 80/9

x = 4

Thus time taken by B to complete the work alone = 5x = 20 days

correct answer c) 20

Other posts related to Quantitative Aptitude – Modern Maths

Permutation and Combination – Fundamental Principle of Counting
Permutation and Combination – Distribution of Objects
How to find Rank of a Word in Dictionary (With or Without Repetition)
Set Theory- Maximum and Minimum Values
How to solve questions based on At least n in Set Theory for CAT Exam?
Sequence and Series Problems and Concepts for CAT 2017 Exam Preparation
Basic Probability Concepts for CAT Preparation