Bissoy.com
Doctors Medicines MCQs Q&A

A alone can complete work in 12 days and B alone can complete work in 15 days. If A and B work for 3 days, then C join them to complete the work where C alone can complete work in 30 days. Find the total number of days taken by all three to complete work.

A alone can complete work in 12 days and B alone can complete work in 15 days. If A and B work for 3 days, then C join them to complete the work where C alone can complete work in 30 days. Find the total number of days taken by all three to complete work. Correct Answer 6 days

Given,

A's 1 day’s work = 1/12

B's 1 day’s work = 1/15

C's 1 day’s work = 1/30

(A + B)’s 1 day’s work = 1/12 + 1/15

= 3/20

A and B 3 days’ work = 3 × 3/20 = 9/20

Remaining work = 1 - 9/20 = 11/20

(A + B + C)’s 1 day’s work

= 1/12 + 1/15 + 1/30

= 11/60

Total time taken by three to complete 11/20th fraction of work

= 11/20 × 60/11

= 3 days

Total time taken to complete the work

= 3 + 3

= 6 days.

Related Questions

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.
Each question presents a situation and asks you to make a judgement regarding that particular circumstance. Choose an answer based on given information. Himanshu and his two friends were walking on the footpath along the road. Suddenly a car drove by and hit a man, who was crossing the road. Each of them remembers certain number of the 6-digit number plate. All three of them went to police station to file a complaint. When asked about the plate number each of them remembers different numbers. 1. All three confirmed that first two numbers from the left was 35. 2. All three agrees than 4th number from the left was 7. 3. All three agrees that there was no even number in the number plate. 4. All three agrees that two numbers were same. Which of the following would be most likely the number of the number plate?
Raj alone can complete the work in 20 days and Radha alone can complete the work in M days while Ram alone can complete the work in 24 days. Raj and Radha can complete half of the work in 6 days. Radha works for 18 days then Raj and Ram join her to complete the remaining work. In what time total work gets completed?
The following question has three statements. Study the question and the statements and decide which of the statement(s) is necessary to answer the question. In how many days will A and B together complete 90% of the given work? I. A can alone complete 40% of the work in 16 days. II. B can alone complete 60% of the work in 30 days. III. Time taken by A to complete the work alone is equal to the time taken by B to complete 80% of the work alone.
Given below are two quantities named 1 and 2. Based on the given information, you have to determine the relationship between the two quantities. You should use the given data and your knowledge of Mathematics to choose between the possible answers. Quantity 1: P and Q can do a work in 6 days and Q and R can do a work in 60/7 days and P and R can do a work in 20/3 days. If Q and R work for first 2 days and left the work. Find the total time taken by P to complete the remaining work. Quantity 2: A and B can do a work in 8/3 days, B and C can do the same work in 3 days and A and C can do the same work in 24/5 days. In what time C alone can complete the work?
Each question presents a situation and asks you to make a judgement regarding that particular circumstance. Choose an answer based on given information. Three friends are waiting for a train on the railway station. Suddenly, a train passes by and each of them tries to remember the train number of the train written on each of the coaches. The train number was a 5-digit number. All must agree in order to confirm the digit of train number. 1. All three agrees that all the digits of the train number was different. 2. All three agrees that the difference of 3rd and 5th digit from left is equal to the 4th digit from the left. 3. All three agrees that the 1st digit was 1. 4. All three agrees that the 2nd digit was an even prime number. Which of the following would be most likely the train number?
Rahim has invited his three buddies over to watch the basketball game on his wide-screen television. They are all hungry, but no one wants to leave to get food. Just as they are arguing about who should make the food run, a commercial comes on for a local pizzeria that delivers. The phone number flashes on the screen briefly and they all try to remember it. By the time Zachary grabs a pen and paper, each of them recollects a different number.i. All of the men agree that the first three numbers are 995.ii. Three of them agree that the fourth number is 9.iii. Three agree that the fifth number is 2.iv. Three agree that the sixth number is 6; three others agree that the seventh number is also 6.Which of the numbers is most likely the telephone number of the pizzeria?
Zachary has invited his three buddies over to watch the basketball game on his wide-screen television. They are all hungry, but no one wants to leave to get food. Just as they are arguing about who should make the food run, a commercial comes on for a local pizze-ria that delivers. The phone number flashes on the screen briefly and they all try to remember it. By the time Zachary grabs a pen and paper, each of them recollects a different number.

#1 : All of the men agree that the first three numbers are 995.
#2 : Three of them agree that the fourth number is 9.
#3 : Three agree that the fifth number is 2.
#4 : Three agree that the sixth number is 6; three others agree that the seventh number is also 6.

Which of the numbers is most likely the telephone number of the pizzeria?
In a group of 450 students, 22% of the total students take the Hindi subject, 34% of the total students take the Physics subject, and 26% of the total students take the Social Science subject. 8% of the total students have taken both Hindi and Physics subject only. Out of the total students in the Hindi subject, 1/3 have taken both Hindi and Social Science subject only. Out of the total students in the Physics subject, 1/3 have taken both Physics and Social Science subject only. Only 20 students take all the three subjects. Find the number of students who have not taken any subject.  
In a group of 450 Teachers, 22% of the total Teachers take the English department, 34% of the total Teachers take the quant. department, and 26% of the total Teachers take the LR department. 8% of the total Teachers have taken both English and quant department only. Out of the total Teachers in the English department, 1 / 3 have taken both English and LR department only. Out of the total Teachers in the quant department, 1 / 3 have taken both quant and LR department only. Only 20 Teachers take all the three departments. Find the number of Teachers who have not taken any department.