Bissoy.com
Doctors Medicines MCQs Q&A

A and B can make the wall in 15 days and 20 days respectively. While C can destroy the entire wall in some fixed day. If A, B, and C starts working together then the wall is completed in 30 days. How many days can C alone destroy an entire wall?

A and B can make the wall in 15 days and 20 days respectively. While C can destroy the entire wall in some fixed day. If A, B, and C starts working together then the wall is completed in 30 days. How many days can C alone destroy an entire wall? Correct Answer 12 days

GIVEN:

⇒ A = 15 days

⇒ B = 20 days

⇒ A + B + C = 30 days

FORMULA USED:

⇒ EFFICIENCY (E) = WORK (W) / TIME (T)

CALCULATIONS:

[ alt="F1 Ashish.S 25-09-20 Savita D2" src="//storage.googleapis.com/tb-img/production/20/10/F1_Ashish.S_25-09-20_Savita_D2.png" style="width: 406px; height: 98px;">

⇒ A + B + C = 2

⇒ 4 + 3 + C = 2

⇒ C = 2 – 7 = - 5

⇒ C = - 5 (i.e. C can breaks 5 bricks per day) ….(1)

⇒ C = 60/5 = 12 days

∴ C can break the entire wall in 12 days.

Related Questions

In a school, a Science project has been assigned to three students Rajat, Rohan, and Bishal and it was told that they should work together on that project. Working alone Rohan can finish the project in 20 days, it is also given that if Rajat and Bishal work on the project they will take 9 days to complete the project. Bishal alone can complete the project in 15 days. Rohan started working on the project from Monday but after 8 days he left and after that Rajat and Bishal started working on it but Bishal also left 6 days before completion of the work and Rajat completed the remaining project, in how many days will the project be completed and on which day will it be completed?
Each of the question below consists of a question and three statements number I, II and III given below it. You have to decide whether the data provided in the statement are sufficient to answer the question. Two person X and Y together can make 25% of total number of bricks in 4.8 days. Another person Z can make 50 bricks in a day. What is the time taken by person X and Z together to make the total number of bricks? I. Dimensions of a brick is (3cm × 4cm × 5cm) while the dimension of a cuboids when all the bricks are put together is (72cm × 80cm × 50cm) and ratio of number of days taken by X and Y alone to make the total number of bricks is 3 : 2. II. The total number of bricks is 4800 and person Y can make 150 bricks in day. III. Total volume of all the bricks together is 1.008m3 and dimension of a bricks is (5cm × 6cm × 7cm) and time taken by Z to make total number of bricks is 200 % more than the total time taken by person Y to make total number of bricks.
Given below are two quantities named A & B. Based on the given information, you have to determine the relation between the two quantities. You should use the given data and your knowledge of Mathematics to choose between the possible answers. Quantity A: A and B together, B and C together and C and A together can complete a piece of work in 10, 12 and 20 days respectively. In how many days can B finish the work alone? Quantity B: P & Q working alone can complete a wok in 20 and 30 days respectively. They started together but after 9 days P left, in how many days will the total work be completed?
P alone can complete the work in 20 days, Q alone can complete the work in 30 days while R alone can complete the work in 10 days. They start working in turns as P works on first day, Q on second day and R on third day, so on till sixth day. On seventh day, all three worked together to complete remaining work. Find the approx. time in which whole work is completed.
A and B together work for 3 days, B then worked alone for 2 days, A then worked alone for 3 days and the work was finished. If A works for 8 days alone and B works for 4 days alone, the work will be finished. How many days will A alone work if B works for 5 days alone?
P alone can complete the work in 12 days and Q alone can complete the work in 24 days. If P works alone for the first day and Q alone works for second day, after second day P and Q works together for next 5 days. After 7 days, R who has same work efficiency as Q, joins P and Q. In how many days, work will be completed?
In the following question, two statements are numbered as A and B. On solving these statements, we get quantities A and B respectively. Solve both quantities and choose the correct option. Quantity A: A can do a piece of work in 10 days and B can do the same work in 15 days. They start working together and after 4 days, A left the work. Find in how many days the total work will be completed. Quantity B: P can do a piece of work in 15 days and Q can do the same work in 25 days. They start working together and after 5 days, Q left the work. Find in how many days the remaining work will gets completed.
J completed a piece of work in 7 days, working 4 hours in a day while K completed a piece of work in 5 days working 7 hours in a day. In how many days can they together complete double of the work working 14 hours a day? 
Two men and women are entrusted with a task. The second man needs three hours more to cope up with the job than the second man and the woman would need working together. The first man, working alone, would need as much time as second man and the woman working together. The first man working alone, would spend eight hours less than the double period of the time second man would spend working alone. How much time would the two men and the women need to complete the task if they all asked together?
A and B can do a piece of work in 30 days and 45 days respectively. They work together for 10 days and after that A goes on leave for 10 days and B works on every alternate day for the next 10 days and then goes on leave for the next 10 days after which A starts the work on every alternate day for the next 10 days. After that A and B together complete the remaining work. Find in how many days the work was completed.