## Time & Work Solved Questions For IBPS, SBI and Other Bank Exams - Page 1

You will find 8 problems in 2 pages..

Time & Work Solved Questions (Page 1 of 2)

Below you will find important formulas of time & work problems. Following that you will find solved questions. These questions will help you in preparation for all bank exams including IBPS, SBI, RRB and other banks.

Basic Formulas:

If A does a piece of work in n days, then the work done by A in 1 day = 1/n

If A is thrice as good as B in work, then

Ratio of work done by A and B = 3 : 1

Ratio of time taken to finish a work by A and B = 1 : 3

If M1 men can do W1 work in D1 days working H1 hours per day and M2 men can do W2 work in D2 days working H2 hours per day (where all men work at the same rate), then

M1 D1 H1 / W1 = M2 D2 H2 / W2

If A can do a piece of work in p days and B can do the same in q days, then A and B together can complete the work in pq / (p+q) days

Question 1

Prakash can complete a piece of work in 24 days and Praveen can complete the same piece of work in 36 days. If Prakash and Praveen work together, how long would they take to complete the work?

a) 14.4 days b) 15.5 days c) 12 days d) 20 days

Solution :

Prakash can complete in one day = 1/24 of work.
Praveen can complete in one day = 1/36 of work.
Prakash and Praveen can complete in one day = 1/24 + 1/36 of work.
= 3 + 2 / 72
= 5/72
Both can complete the work in 72/5 days.i.e., 14.4 days

Usually we will solve these type of problems in the above method.There is another alternate method to solve these type of problems.
i.e., we can solve by using LCM method instead of fraction method.

Alternate Method :

L.C.M of 24 and 36 is 72.
For eg, let us assume that they are preparing documents.
72 is the total document, they have to complete.
Prakash alone can complete 72 documents in 24 days, then in one day he will complete 3 documents.
Praveen alone can complete 72 documents in 36 days, then in one day he will complete 2 documents.
By working together they can complete 5 (3 + 2)documents in one day.

We have solved many such problems by starting with the statement, that if a man does a job in 8 days, he will do 1/8 th of the job in 1 day.
The L.C.M. method would ensure that you do not handle fractions till the very end.
For this problem, take the L.C.M of 24 and 36 which is 72.
Therefore, they can complete 72 documents in 14.4 (72/5) days.

Question 2

Bala and Aruna can complete a work in 30 days. Bala can do it alone in 50 days. How many days would Aruna take to complete the work alone?

a) 100 days b) 120 days c) 90 days d) 75 days

Solution :

By using the alternate method as mentioned in Question 1, we are going to solve further problems.

LCM of 30 and 50 is 150.
Bala and Aruna can complete whole work in 30 days. In 1 day they can complete 5(150/30) of the work.
Bala alone can can complete whole work in 50 days. In 1 day he can complete 3(150/30) of the work.
Aruna alone can complete in 1 day (5 - 3)of the work.
Therefore, Aruna will complete the whole work in 150/2 = 75 days.

Question 3

P can wash some number of clothes in 6 hours and Q can wash same in 18 hours. After 4 hours, P leaves from his job. Then how long must Q work to
wash the remaining clothes?

a) 6 hours b) 12 hours c) 8 hours d) 4 hours

Solution :

The L.C.M of 6, 18, and 4 is 36. so assume that the total number of clothes is 36.
36 clothes can be washed by P in 6 hours.Hence P’s speed is 6 =(36/6) clothes per hour.
Before P's absent, he would have washed 6x4 i.e. 24 clothes.
The remaining is 12 clothes, which will be done by Q in 6 = (18/36 x 12) hours. (as it is indicated that the entire job can be finished by Q in 18 hours)
Hence the answer is 6 hours.

Question 4

Vanitha can type a file in 10 hours. Her friend joins after 3 hours.Together they type for 4 hours to complete the file. How many hours would her friend take to type the file alone?

a) 13 1/3 hours b) 12 1/5 hours c) 11 1/2 hours d) 10 1/7 hours

Answer : a) 13 1/3 hours.

Solution :

In some cases, instead of L.C.M you can take multiples of L.C.M or simply multiply the number involved in the problem.
In this problem, the numbers involved are 10, 3 and 4.
Multiplying all of them, we get 120 which is the number of files to be typed.

Vanitha can type 120 files in 10 hours, so in 1 hour 12 files.
She works alone for 3 hours to produce 3x12 files before a helper joins.
Together they finish the balance requirement of 120-36 = 84 in 4 hours, so in 1 hour 21(84/4) files are completed.
But out of this 21, Vanitha is producing 12 files per hour.
Therefore, her friend must be producing 9 files per hour.
If her friend alone types 120 files, then she will complete in 120/9 hours i.e.,13 1/3 hours.

Time & Work Solved Questions (Page 1 of 2)

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