CAT Exam  >  CAT Questions  >  9. A and B can do a piece of work in 18 days;... Start Learning for Free
9. A and B can do a piece of work in 18 days; B and C can do it in 24 days, A and C can do it in 36 days. In how many days B alone can finish the work?
Most Upvoted Answer
9. A and B can do a piece of work in 18 days; B and C can do it in 24 ...
Given information:
A + B = 1/18
B + C = 1/24
A + C = 1/36

To find: Number of days it takes for B to finish the work alone.

Let's solve the problem step by step.

Step 1: Find the individual efficiencies of A, B, and C.

Let's assume the efficiency of A is x units per day, the efficiency of B is y units per day, and the efficiency of C is z units per day.

From the given information, we can write the following equations:

x + y = 1/18 ...(1)
y + z = 1/24 ...(2)
x + z = 1/36 ...(3)

Step 2: Solve the equations (1), (2), and (3) simultaneously.

To solve the equations, we can use the method of substitution or elimination. Here, we will use the elimination method.

Multiplying equation (1) by 24, equation (2) by 18, and equation (3) by 36, we get:

24x + 24y = 1/18 * 24 ...(4)
18y + 18z = 1/24 * 18 ...(5)
36x + 36z = 1/36 * 36 ...(6)

Simplifying equations (4), (5), and (6), we get:

24x + 24y = 4/3 ...(7)
18y + 18z = 3/4 ...(8)
36x + 36z = 1 ...(9)

Multiplying equation (7) by 3, equation (8) by 4, and equation (9) by 4, we get:

72x + 72y = 4 ...(10)
72y + 72z = 3 ...(11)
144x + 144z = 4 ...(12)

Subtracting equation (11) from equation (10), we get:

72x + 72y - (72y + 72z) = 4 - 3
72x - 72z = 1 ...(13)

Adding equation (12) to equation (13), we get:

144x + 144z + 72x - 72z = 4 + 1
216x = 5
x = 5/216

Substituting the value of x in equation (3), we get:

(5/216) + z = 1/36
z = 1/36 - 5/216
z = 6/216 - 5/216
z = 1/216

Substituting the values of x and z in equation (1), we get:

(5/216) + y = 1/18
y = 1/18 - 5/216
y = 12/216 - 5/216
y = 7/216

Step 3: Find the number of days B alone can finish the work.

We know that B's efficiency is y units per day.
Therefore, B can finish the work alone in (1/y) days.

Substituting the value of y, we get:

(1/(7/216)) = 216/7

Thus, B alone can finish the
Community Answer
9. A and B can do a piece of work in 18 days; B and C can do it in 24 ...
180

Explore Courses for CAT exam

Top Courses for CAT

Question Description
9. A and B can do a piece of work in 18 days; B and C can do it in 24 days, A and C can do it in 36 days. In how many days B alone can finish the work? for CAT 2025 is part of CAT preparation. The Question and answers have been prepared according to the CAT exam syllabus. Information about 9. A and B can do a piece of work in 18 days; B and C can do it in 24 days, A and C can do it in 36 days. In how many days B alone can finish the work? covers all topics & solutions for CAT 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for 9. A and B can do a piece of work in 18 days; B and C can do it in 24 days, A and C can do it in 36 days. In how many days B alone can finish the work?.
Solutions for 9. A and B can do a piece of work in 18 days; B and C can do it in 24 days, A and C can do it in 36 days. In how many days B alone can finish the work? in English & in Hindi are available as part of our courses for CAT. Download more important topics, notes, lectures and mock test series for CAT Exam by signing up for free.
Here you can find the meaning of 9. A and B can do a piece of work in 18 days; B and C can do it in 24 days, A and C can do it in 36 days. In how many days B alone can finish the work? defined & explained in the simplest way possible. Besides giving the explanation of 9. A and B can do a piece of work in 18 days; B and C can do it in 24 days, A and C can do it in 36 days. In how many days B alone can finish the work?, a detailed solution for 9. A and B can do a piece of work in 18 days; B and C can do it in 24 days, A and C can do it in 36 days. In how many days B alone can finish the work? has been provided alongside types of 9. A and B can do a piece of work in 18 days; B and C can do it in 24 days, A and C can do it in 36 days. In how many days B alone can finish the work? theory, EduRev gives you an ample number of questions to practice 9. A and B can do a piece of work in 18 days; B and C can do it in 24 days, A and C can do it in 36 days. In how many days B alone can finish the work? tests, examples and also practice CAT tests.
Explore Courses for CAT exam

Top Courses for CAT

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev