Time and Work Questions

FACTS  AND  FORMULAE  FOR  TIME  AND  WORK  QUESTIONS

 

 

1. If A can do a piece of work in n days, then A's 1 day's work =1n

2. If A’s 1 day's work =1n, then A can finish the work in n days.

 

3. A is thrice as good a workman as B, then:

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

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

 

NOTE : 

Efficiency1No of time units

 

 Efficiency × Time = Constant Work

 

Hence, Required time = WorkEfficiency

 

Whole work is always considered as 1, in terms of fraction and 100% , in terms of percentage.

In general, number of day's or hours = 100Efficiency

Q:

A group of men can complete a job in K hours. After every 4 hours, half the number of men working at that point of time leave the job. Continuing this way if the job is finished in 16 hours, what is the value of K ?

A) 7 hrs B) 7.5 hrs
C) 8 hrs D) 8.25 hrs
 
Answer & Explanation Answer: B) 7.5 hrs

Explanation:

Let there are L men

job requires LK man hours.

 

job completed in first 4 hrs = L x 4 = 4L

job completed in next 4 hrs = 4 x L/2 = 2L

job completed in next 4 hrs = 4 x L/4 = L

job completed in last 4 hrs = 4 x L/8 = L/2

4L + 2L + L + L/2 = KL

K = 7+1/2 = 7.5 hours.

Report Error

View Answer Report Error Discuss

Filed Under: Time and Work
Exam Prep: TOEFL , GRE , GATE , CAT , Bank Exams , AIEEE
Job Role: Bank PO , Bank Clerk , Analyst

5 7279
Q:

A can do a work in 24 days. B is 20% more efficient than A. If C can do the work in 10 more days than B, find the time taken by A and C together to complete the work.

A) 43/3 days B) 40/3 days
C) 50/3 days D) 41/2 days
 
Answer & Explanation Answer: B) 40/3 days

Explanation:

A takes 24 days to complete a work.
B is 20% more efficient than A,
hence B will take (24*100)/120 = 20 days.
C takes (20+10) = 30 days.
Time taken by A & C in completing the work = (24*30)/(24+30) = (24*30)/54 = 40/3 days.

Report Error

View Answer Report Error Discuss

Filed Under: Time and Work
Exam Prep: Bank Exams

0 7274
Q:

Sixty men can stitch 150 shirts in 30 days working 8 hours a day. In how many days can 35 men stitch 200 shirts working 6 hours a day ?

A) 87.5 B) 89
C) 91.5 D) 93.5
 
Answer & Explanation Answer: C) 91.5

Explanation:

We have M1 D1 H1 / W1 = M2 D2 H2 / W2 (Variation rule)
(60 x 30 x 8)/ 150 = (35 x D2 x 6) / 200
D2 = (60 x 30 x 8 x 200) / (150 x 35 x 6) => D2 = 91.42 days =~ 91.5 days.

Report Error

View Answer Report Error Discuss

Filed Under: Time and Work
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Bank Clerk , Bank PO

5 7251
Q:

A take twice as much time as B or thrice as much time to finish a piece of work. Working together, they can finish the work in 2 days. B can do the work alone in ?

A) 3 hrs B) 6 hrs
C) 7 hrs D) 5 hrs
 
Answer & Explanation Answer: B) 6 hrs

Explanation:

Suppose A, B and C take x, x/2 and x/3 respectively to finish the work.
Then, (1/x + 2/x + 3/x) = 1/2
6/x = 1/2 => x = 12
So, B takes 6 hours to finish the work.

Report Error

View Answer Report Error Discuss

Filed Under: Time and Work
Exam Prep: AIEEE , Bank Exams , CAT
Job Role: Bank Clerk , Bank PO

5 7167
Q:

The ratio of efficiencies of P, Q and R is 2 : 3 : 4. While P and R work on alternate days and Q work for all days. Now the work completed in total 10 days and the total amount they get is Rs. 1200. Find the amount of each person(respectively).

A) 200, 600, 400 B) 400, 600, 200
C) 600, 200, 400 D) 400, 200, 600
 
Answer & Explanation Answer: A) 200, 600, 400

Explanation:

Ratio of efficiencies of P, Q and R = 2 : 3 : 4

From the given data,

Number of working days of P, Q, R = 5 : 10 : 5

Hence, ratio of amount of p, Q, R = 2x5 : 3x10 : 4x5 = 10 : 30 : 20

Amounts of P, Q, R = 200, 600 and 400.

Report Error

View Answer Report Error Discuss

Filed Under: Time and Work
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Analyst , Bank Clerk , Bank PO

8 7143
Q:

In a hostel, there was food for 1000 students for one month. After 10 days, 1000 more students joined the hostel. How long would the students be able to carry on with the remaining food?

A) 10 days B) 15 days
C) 20 days D) 5 days
 
Answer & Explanation Answer: A) 10 days

Explanation:

After 10 days, the remaining food would be sufficient for the 1000 students for 20 more days

-->If 1000 more students are added, it shall be sufficient for only 10 days (as the no. of students is doubled, the days are halved).

Report Error

View Answer Report Error Discuss

Filed Under: Time and Work
Exam Prep: GATE , CAT , Bank Exams
Job Role: Bank PO , Bank Clerk

10 7084
Q:

Ten women can do a work in six days. Six men can complete the same work in five days. What is the ratio between the capacity of a man and a woman?

A) 1:2 B) 2:1
C) 2:3 D) 3:2
 
Answer & Explanation Answer: B) 2:1

Explanation:

(10 * 6) women can complete the work in 1 day.

 Therefore, 1 woman's  1 day's work = 1/60

 

(6 * 5) men can complete the work in 1 day.

 Therefore, 1 man's  1 day's work = 1/30

 

so, required ratio =1/30 : 1/60 = 2:1

Report Error

View Answer Report Error Discuss

Filed Under: Time and Work

4 7026
Q:

At Arihant Prakasham every book goes hrough 3 phases (or stages) typing, composing and binding. There are 16 typists, 10 composers and 15 binders. A typist can type 8 books in each hour, a composer can compose 12 books in each hour and a binder can bind 12 books in each hour. All of the people at Arihant Prakasham works for 10 hours a day and each person is trained to do only the ob of 1 category.How many books can be prepared in each day?

A) 1500 B) 1200
C) 1440 D) 1380
 
Answer & Explanation Answer: B) 1200

Explanation:

T                 C              B

16              10             15

8                12             12

128            120           180             <------- in one hour

1280          1200         1800            <------- in 10 hours

Since, restriction is imposed by composers i.e,since only 1200 books can be composed i 10 hours so not more than 1200 books can be finally pepared.

 

Report Error

View Answer Report Error Discuss

Filed Under: Time and Work

8 7013