304 North Cardinal St.
Dorchester Center, MA 02124

# Practice Important Work Time Questions

-

Work Time question are very important for most of the exam specially in banking exam. There are always few question related to work time in the Bank, IBPS, SBI PO clerk exams and you can expect those to asked again in upcoming exams

We have listed some very important tip and tricks for solving work time Question in quick way. Also there are important Work time question for practicing. Please try these question thoroughly and practice as much question you can.

Tips to Solve Work Time Question Fast:

Use Efficiency method to Solve work time Questions:

Next Example: A takes 8 day to finish a piece of work. B takes 10 days to finish the same work. C takes 20 days to finish the work. D takes 40 days to finish the work. How long will it take to finish the work when all of them are working together?

-

Answer: Try yourself first and then check

Case 1 – A does a work in X days, B does a Work in Y days In how many days they will complete the work.

Question- A completes the work in 10 days and B completes the work in 15 days In how many days they will complete the work.

Efficiency method.
Efficiency of A =100/10 = 10%

-

Efficiency of B = 100/15 = 6.66%

Efficiency of A & B Together = 10+ 6.66 = 16.66%

So the time taken by A & B together to Complete the work will be 100/16.66 = 6 Days.

##### Case -2 A can do a work in X days and B can do it Y days, In how many days the work is completed if they work alternatively Started by A.

Efficienecy Method

A’s Efficiency = 10%

B’s Efficiency = 6.66%

A + B Efficiency = 16.66%

Work done by A and B in 2 days [ Remember 2 days because they are not working together but working alternatively] = 16.66%

So time taken by them to complete 100% work = 100/(16.66 = 6 [ but always remember multiply this by 2, Because 16.66% work is done by them in 2 days and not in 1 day.

Answer will be 6*2 = 12 days.

### Case 3: A can do a work in X days, B can do the work Y days and A leaves after working Z days.

##### Question- A can do a work in 10 days and B can do it in 15 days, A works for 2 days and then leaves, In how many days will the work be completed?

Efficiency method

A’s efficiency = 10%

B’s Efficiency = 6.66%

Total a+b = 16.66%

Work done by A and B together in 2 days = 16.66*2 = 33.33%

Work remaining = 66.66%

Time taken by B to complete 66.66% work = 66.66/6.666 = 10 days

Total time = 10+2 = 12 days

##### Case 4 : A can do a piece of Work in 10 days and B can do it in 15 days, In how many days will the work be completed if B leaves 2 days before the completion on work.

Efficiency method

A’s efficiency = 10%

B’s efficiency = 6.66%

Total = 16.66%

Work will be completed in 6 days

Work done in 4 days = 66.66%

Remaining = 33.33%

A will complete the remaining in = 33.33/10 = 3.33

Total = 4+3.33 = 7.33

##### Examples on “LCM method for time and work problems”

Example 1 :

A can do a piece of work in 8 days. B can do the same in 14 days. In how many days can the work be completed if A and B work together?

Solution :

Let us find LCM for the given no. of days “8” and “14”.

L.C.M of (8, 14) = 56

Therefore, total work = 56 units

A can do =  56 / 8 =  7 units/day

B can do = 56 / 14 =  4 units/day

(A + B) can do = 11 units per day

No. of days taken by (A+B) to complete  the same work

= 56 / 11 days

Examples

Q1. Ash can do a job in 10 days. Bali can do the same job in 5 days. In how many days they can complete the job if they work together?

1. 6 days
2. 3.33 days
3. 7.25 days
4. 7.5 days
5. None of these

Ans: 3.33 days

Solution: Ash can do a job in 10 days,

So efficiency of Ash = 100/10 = 10%

Similarly, Bali’s efficiency = 100/5 = 20%

Combined efficiency of Ash + Bali per day becomes = 20 + 10 = 30%

Now, we have to find out the number of days taken by both Ash and Bali to do 100% work,

Since they can do 30% wok in 1 day,

So, they will 100% work in 100/30 = 3.33 days

Q2: A can do a work in 6 days and B can do the same work in 5 days. The contract for the work is Rs 220. How much shall B get if both of them work together?

Shortcut trick : As wages distributed in inverse proportion of number of days, their share should be in the ratio 5:6

B’s share = 220/11 * 6 = 120

Most of the time and work questions can be solved if you know the basic correlation between time, work and man-hours.