Quantitative Aptitude

Time and Work

2,195 Questions
All Pairwise rates and staged schedules 440 Workers-days-hours chain rule 439 LCM units and efficiency ratios 409 Different worker categories 311 Combined rates and an unknown worker 257 Division of wages 219 Alternate work 110 Opposing rates 10

Time and Work Questions

Multiple choice

$A$ alone can do a piece of work in $6$ days and $B$ alone in $8$ days. $A$ and $B$ undertook to do it for $Rs. 3200.$ With the help of $C,$ they completed the work in $3$ days. How much is to be paid to $C$?
  1. $300$
  2. $400$
  3. $600$
  4. $800$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A's daily work is 1/6 and B's is 1/8. In 3 days, A does 3/6 = 1/2 and B does 3/8 of the work. Together they do 1/2 + 3/8 = 7/8 of the work, leaving 1/8 for C. Since C does 1/8 of the total work, C's share is 1/8 of 3200, which is 400.

Multiple choice

$12$ men can complete a piece of work in $4$ days while $15$ women can complete the same work in $4$ days $6$ men start working on the job and after working for $2$ days all of them stopped working. How many women should be put on the job to complete the remaining work if it is to be completed in $3$ days ?
  1. $15$
  2. $18$
  3. $22$

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

12 men = 4 days work, so 1 man = 48 days work. 15 women = 4 days work, so 1 woman = 60 days work. 6 men work for 2 days = 6 * 2 = 12 man-days. Total work = 48 man-days. Remaining work = 48 - 12 = 36 man-days. 36 man-days = 36 * (60/48) = 45 woman-days. To finish in 3 days, women needed = 45 / 3 = 15.

Multiple choice

A is thrice as efficient as B and B is twice as efficient as C. if A, B and C work together , how long will they take to complete a job which B complete in $10$ days ?
  1. $\displaystyle \frac{20}{9}$ days
  2. $\displaystyle \frac{11}{9}$ days
  3. $3$ days

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A=3B, B=2C. So A=6C, B=2C. If B takes 10 days, the total work is 10 * B's rate. A+B+C rate = 6C + 2C + C = 9C. B's rate = 2C. Total work = 10 * 2C = 20C. Time = 20C / 9C = 20/9 days.

Multiple choice

A and B together can complete a work in 12 days A alone can complete it in 20 days If B now does the work for half a day dally Then in how many days A and B together will complete the work?

  1. 15 days

  2. 20 days

  3. 45 days

  4. 30 days
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A and B together complete 1/12 of the work per day, while A alone completes 1/20. Therefore, B completes 1/30 per day. If B works for half a day daily, B contributes 1/60 daily, and A plus this contribution completes 1/15 per day, requiring 15 days.

Multiple choice

A, B and C complete a work working alone in 10, 15 and 20 days respectively If all of then work together to complete the work what fraction of the work would have done by B?
  1. $\displaystyle \frac{4}{13}$
  2. $\displaystyle \frac{1}{2}$
  3. $\displaystyle \frac{1}{3}$
  4. $\displaystyle \frac{6}{13}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A, B, and C complete work in 10, 15, and 20 days. Their rates are 1/10, 1/15, and 1/20. Total rate = 6/60 + 4/60 + 3/60 = 13/60. The fraction of work done by B is (Rate of B) / (Total Rate) = (1/15) / (13/60) = 4/13.

Multiple choice

$12$ children can complete a piece of work in $21$ days. Approximately, how many children will be required to complete the same piece of work in $15$ days?(Approximately)
  1. $24$
  2. $14$
  3. $22$
  4. $17$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Using the inverse proportion formula (M1*D1 = M2*D2), we have 12 * 21 = M2 * 15. Solving for M2 gives (12 * 21) / 15 = 252 / 15 = 16.8. Since the number of children must be an integer, 17 is the closest approximation.