QUIZ - 1 (T & W)

Time & Work Quiz - 1

1. A and B together can do a piece of work in 8 days. If A alone can do the same work in 12 days, then B alone can do the same work in?


20 days
16 days
28 days
24 days
None of these


2. A can do a piece of work in 4 days. B can do it in 5 days. With the assistance of C they completed the work in 2 days. Find in how many days can C alone do it?


20 days
5 days
10 days
12 days
None of these


3. A and B can do a piece of work in 3 days, B and C in 4 days, C and A in 6 days. How long will C take to do it?


18 days
20 days
24 days
30 days
None of these


4. A can do a job in 18 days and B can do it in 30 days. A and B working together will finish twice the amount of work in _____ days?


21 1/2 days
22 1/2 days
23 1/2 days
12 1/2 days
None of these


5. A and B working separately can do a piece of work in 9 and 12 days respectively. If they work for a day alternately. If A begins first, in how many days the work will be completed?


10 1/2 days
10 1/4 days
10 2/3 days
10 1/3 days
10 3/4 days

Question of the day

QUESTION OF THE DAY - 30/09/2016

A bag contains 375 currency notes consisting of 5 rupee, 10 rupee and 50 rupee currencies in the ratio 4 : 8 : 3 respectively. Out of this Rs 50 is spent and the left out money is exchanged for 100 rupee currency notes. Then the number of 100 rupee currency notes is ___

1. 62
2. 52
3. 72
4. 68
5. 50

Time & Work ( Part - 5)

Working Alternate Days

So far we have seen problems based on individual work, group work and working in pairs, and asked to find individual work or group work depending on the question. I hope that you people enjoying these posts and updating yourself. In this post iam providing stuff about the concept of people working alternate days.

Working alternate days means.... lets consider A and B are employed in a work and they are working alternate days. That means one day A is working and the other day B is working on the same work. And completes the work.

NOTE: It is important that who is starting the work.

Let's understand this concept by an example:

Q: A and B are employed to finish a work. A alone can complete the work in 10 days while B alone in 15 days. If they work on alternate days, starting with A, find the number of days taken to finish the job?

Sol:   Here A is working on 1st day. [A B A B A B A B ... This is the pattern]

          A ----  10          6

                            60 (Total work)

          B ----  15          4

  

Day - 1: A  does 6 work

Day - 2: B  does 4 work

i.e., in 2 days -----> 10 work is done

           2*6 days -----> 10*6 = 60 work

thus, 12 days required to complete the work.

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Q: A and B working separately can do a piece of work in 20 and 24 days. They work on alternate days starting with B on the first day. In how many days will the work be completed?

1. 23 days
2. 22 days
3. 21 (5/6) days
4. 21 days

Sol: A ---- 20             6

                         120

       B ---- 24             5

B is starting, B A B A B A B A ....

                     2 days ------ 11 work

       2*10 = 20days ------  11*10 = 110 work

Remaining work = 120 - 110 = 10

                    21st day B --- 5 work

              Remaining work is 10 - 5 = 5

This is done by A in 5/6 days (not a complete day).

 Hence, Total days = 21(5/6) days.

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Try this:

Q: A, B and C can do a work in 6, 10 and 8 days respectively, working individually. They started the work doing alternately. Find the number of days required to complete the work, if

(a) A started the work.

(b) B started the work.

(c) C started the work.

Post your answer in comment box below. Solution is provided soon...

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Time & Work ( Part - 4)

Persons working in PAIRS

When questions are asked about people working in pairs, and asked to find the combined work and hence individual work also. Lets understand this concept with the help of following example.

Q: A and B can do a work in 12 days, B and C can do it in 15 days and C and A can complete it in 20 days. If A, B and C work together the work will be completed in how many days?

1. 5 days
2. 47/6 days
3. 10 days
4. 47/3 days
5. None of these

Sol:

              A + B  ------------- 12                 5

              B + C  ------------- 15        60     4

              C + A  ------------- 20                 3

         ------------                                   -------

        2(A+B+C)                                        12

                               2(A+B+C) --------- 60/12 = 5 days

                                  (A+B+C)--------- 5*2 = 10 days

NOTE: To find individual work,

A - alone:

                    A+B+C    -------- 10                 3

                                                          30

                         B+C    -------- 15                 2

                  -----------                                 ------

                        A                                           1

                             A = 30/1 = 30 days

B - alone:

                    A+B+C    -------- 10                 4

                                                          40

                         C+A   --------  20                 2

                  -----------                                 ------

                        B                                           2

                             B = 40/2 = 20 days

C - alone:

                    A+B+C    -------- 10                 6

                                                          60

                         A+B   -------- 12                 5

                  -----------                                 ------

                         C                                           1

                             C = 60/1 = 60 days

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In this way we can proceed to unfold the task. Dear viewers... do practise more and more questions of same kind. And leave a comment if you have any doubts. 

Question of the day

QUESTION OF THE DAY - 27/09/2016

A person sells a table at a profit of 10%. If he had bought the table at 5% less cost and sold for Rs.80 more, he would have gained 20%. The cost price of the table is

1. Rs 3200
2. Rs 2500
3. Rs 2000
4. Rs 3500
5. Rs 2200

Question of the day

QUESTION OF THE DAY - 25/09/2016

The average height of 18 boys in a class is170 cm. If the heights of 15 new boys are added, the new average increase by 3 cm. What is the average height of the 15 new boys?

1. 176.6 cm
2. 172.3 cm
3. 178.4 cm
4. 174.6 cm
5. None of these

Question of the day

QUESTION OF THE DAY - 22/09/2016

Two trains start from P and Q respectively and travel towards each other at a speed of 50 kmph and 40 kmph respectively. By the time they meet, the first train has travelled 100 km more than the second. Then the distance between P and Q is ____

1. 500 km
2. 630 km
3. 660 km
4. 900 km
5. 850 km