Practice Test on Time and Work

In practice test on time and work we have different types of questions to solve and get prepared for 8th grade test on time and work. Objective questions on time and work are given to choose the correct answer from each of the following.

Tick (✔) the correct answer in each of the following:

1. A alone can do a piece of work in 10 days and B alone can do it in 15 days. In how many days will A and B together do the same work?

(a) 5

(b) 6

(c) 8

(d) 9

2. Jack can finish a work in 10 days and Tom can do the same work in half the time taken by A. Then, working together, what part of the same work they can finish in a day?

(a) 3/10

(b) 1/9

(c) 2/5

(d) 2/7

3. A man can do a piece of work in 5 days, but with the help of his son, he can dolt in 3 days. In what time can the son do it alone?

(a) 6¹/₂ days

(b) 7 days

(c) 7¹/₂ days

(d) 8 days

4. White can do a job in 15 days and Lee can do the same job in 9 days. With the help of Scott, they did the job in 3 days only. Then, Scott alone can do the job in __________

(a) 6¹/₅ days

(b) 6²/₅ days

(c) 6³/₇ days

(d) 10 days

5. P can do ¼ of a work in 10 days; Q can do 40% of the work in 15 days and R can do 1/3 of the work in 13 days. Who will complete the work first?

(a) P

(b) Q

(c) R

(d) P and R both

6. A and B are working on an assignment. A takes 6 hours to type 32 pages on a computer while B takes 5 hours to type 40 pages. How much time will they take, working together on two different computers, to type an assignment of 110 pages?

(a) 7 hrs 30 min

(b) 8 hrs

(c) 8 hrs and 15 min

(d) 8 hrs 25 min

7. Smith and Thomas can do a piece of work in 72 days; Thomas and Clark can do it in 120 days; Smith and Clark can do it in 90 days. In what time can Smith, Thomas and Clark do it, working together?

(a) 60 days

(b) 66 days

(c) 75 days

(d) 80 days

8. Clark can do a work in 9 days and Nelson in 15 days. If they work on it together for 5 days then the fraction of the work that is left, is _________ .

(a) 1/15

(b) 1/10

(c) 11/15

(d) 1/9

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9. A can do 1/3 of a work in 5 days and B can do 2/5 of the work in 10 days. In how many days can both A and B together do the work?

(a) 7³/₄ days

(b) 8⁴/₅ days (c) 9³/₈ days

(d) 10 days

10. A pipe can fill a water tank in 8 hours. Due to a leak in the bottom of the water tank, it is filled in 10 hours. If the water tank is full, how much time will the leak take to empty it?

(a) 36 hours

(b) 42 hours

(c) 45 hours

(d) 40 hours

11. A tap can fill a oil tank in 15 hours. After half the oil tank is filled, nine more similar taps are opened. What is the total time taken to fill the oil tank completely?

(a) 3 hrs 15 min

(b) 3 hrs 45 min

(c) 4 hrs

(d) 4 hrs 15 min

12. Two pipes can fill a tank in 10 hours and 12 hours respectively, while a third pipe empties the full tank m 20 hours. If all the three pipes operate simultaneously, in how much time will the tank be full?

(a) 7 hrs 15 mm

(b) 7 hrs 30 mm

(c) 7 hrs 45 mm

(d) 8 hrs

13.One tap can fill a water tank four times as fast as another tap. If together the two taps can fill the water tank in 30 minutes then the slower tap alone will be able to fill the water tank in _______ .

(a) 81 min

(b) 108 min

(c) 150 min

(d) 192 min

Hint. Let the slower pipe alone fill the water tank in t minutes.

Then, faster pipe will fill it in t/4 minutes.

Therefore, 1/t + 4/t = 1/30

⇒ 5/t = 1/30

Now solve for t.