Quantitative Aptitude
TIME AND WORK MCQs
Time & Work, Work And Wages
Total Questions : 1512
| Page 2 of 152 pages
Answer: Option D. -> 90 days
Answer: Option A. -> 1 : 2 : 4
Answer: Option B. -> 5 days
Answer: Option B. -> 21 days
Answer: Option A. -> 24 days
Answer: Option B. -> \(4\frac{1}{2}\)
Answer: Option B. -> 3 days
Question 18.
- Anita, Indu and Geeta can do a piece of work in 18 days, 27 days and 36 days respectively. They start working together. After working for 4 days, Anita goes away and Indu leaves 7 days before the work is finished. Only Geeta remains at work from beginning till end. In how many days was the whole work done?
Answer: Option B. -> 16 days
• The given problem is based on the concept of Work and Time.
• Work is defined as the amount of effort put in by a person to complete a given task.
• Time is the measure of duration or the interval between two events.
• The formula for calculating the work done by three persons working together is
Total Work = 1/ (1/A + 1/B + 1/C)
• Here, A, B and C represents the time taken by each of the three persons to complete the given task.
• In the given problem, A = 18 days, B = 27 days and C= 36 days.
• Therefore, applying the formula,
Total Work = 1/ (1/18 + 1/27 + 1/36)
Total Work = 16 days
• Thus, the whole work was completed in 16 days.
• The given problem is based on the concept of Work and Time.
• Work is defined as the amount of effort put in by a person to complete a given task.
• Time is the measure of duration or the interval between two events.
• The formula for calculating the work done by three persons working together is
Total Work = 1/ (1/A + 1/B + 1/C)
• Here, A, B and C represents the time taken by each of the three persons to complete the given task.
• In the given problem, A = 18 days, B = 27 days and C= 36 days.
• Therefore, applying the formula,
Total Work = 1/ (1/18 + 1/27 + 1/36)
Total Work = 16 days
• Thus, the whole work was completed in 16 days.
Answer: Option C. -> 36 days
Let's assume that the son's speed is x units per day.Then, the father's speed is twice as fast, which means his speed is 2x units per day.
Now, let's consider the job that needs to be completed. Let the total work be W.The time taken by the father to complete the job alone can be calculated using the formula:
time taken = work / rate
where rate is the speed at which the job is done.
So, the father's time taken to complete the job alone is:
W / (2x)
Similarly, the time taken by the son to complete the job alone is:
W / x
Now, let's consider the time taken by the father and son together to complete the job.We know that they can complete the job in 12 days.Using the formula:
work done = rate * time taken
we can write:
W = (2x + x) * 12
Simplifying this equation, we get:
W = 36x
Now, we can substitute the value of W in the above equations to find the time taken by the father and son to complete the job alone.
Time taken by the father alone:
W / (2x) = (36x) / (2x) = 18 days
Time taken by the son alone:
W / x = 36 days
Therefore, the correct answer is option C, 36 days.
To summarize:
Let's assume that the son's speed is x units per day.Then, the father's speed is twice as fast, which means his speed is 2x units per day.
Now, let's consider the job that needs to be completed. Let the total work be W.The time taken by the father to complete the job alone can be calculated using the formula:
time taken = work / rate
where rate is the speed at which the job is done.
So, the father's time taken to complete the job alone is:
W / (2x)
Similarly, the time taken by the son to complete the job alone is:
W / x
Now, let's consider the time taken by the father and son together to complete the job.We know that they can complete the job in 12 days.Using the formula:
work done = rate * time taken
we can write:
W = (2x + x) * 12
Simplifying this equation, we get:
W = 36x
Now, we can substitute the value of W in the above equations to find the time taken by the father and son to complete the job alone.
Time taken by the father alone:
W / (2x) = (36x) / (2x) = 18 days
Time taken by the son alone:
W / x = 36 days
Therefore, the correct answer is option C, 36 days.
To summarize:
- Let x be the son's speed and 2x be the father's speed.
- Let W be the total work that needs to be done.
- Father's time taken to complete the job alone: W / (2x)
- Son's time taken to complete the job alone: W / x
- Using W = 36x, we get father's time taken = 18 days and son's time taken = 36 days.
Answer: Option B. -> 30