Dell Time and work Questions

Dell Quants Time & Work Quiz

Question 1
X and Y can do a piece of work in 20 days and 12 days respectively. 
X started the work alone and then after 4 days, Y joined him till 
the completion of the work. How long did the work last?
A
6 days
B
10 days
C
20 days
D
15 days
Question 1 Explanation: 
Work done by X in 4 days =[1/20 * 4] = 1/5Remaining work =[1-1/5] = 4/5 (X+Y)’s 1 days work= [1/20 + 1/12] = 8/60= 2/15 Now, 2/15 work is done by X and Y in 1 day. So, 4/5 work will be done by X and Y in [15/2 * 4/5] = 6 days Hence, total time taken = (6 + 4) days = 10 days
Question 2
P can complete a work in 12 days working 8 hours a day. 
Q can complete the same work in 8 days working 10 hours a day. 
If both P and Q work together, working 8 hours a day, 
in how many days can they complete the work?
A
5 5/11
B
5 6/11
C
6 5/11
D
6 6/11
Question 2 Explanation: 
P can complete the work in (12 x 8) hrs. = 96 hrs. Q can complete the work in (8 x 10) hrs. = 80 hrs. P’s1 hour’s work =1/96 and Q’s 1 hour’s work =1/80 (P + Q)’s 1 hour’s work = [1/96 + 1/80]= 11/480 So, both P and Q will finish the work in 480/11 hrs Number of days of 8 hours each =[480/11 * 1/8]=60/11 days= 5 5/11 days
Question 3
A certain number of men complete a piece of work in 60 days. 
IF there were 8 men more the work would have been completed 
in 10 days less. How many men were there originally?
A
30
B
35
C
40
D
45
Question 3 Explanation: 
If there are x workers in first case 1 man will take 60x. In second it will be 50(x+8)60x = 50x + 400 x = 40
Question 4
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
Question 4 Explanation: 
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.
Question 5
In the beginning, Ram works at a rate such that he can finish a 
piece of work in 24 hrs, but he only works at this rate for 16 hrs. 
After that, he works at a rate such that he can do the whole work 
in 18 hrs. If Ram is to finish this work at a stretch, 
howmany hours will he take to finish this work?
A
12 hrs
B
18 hrs
C
23/2 hrs
D
22 hrs
Question 5 Explanation: 
Ram’s 16 hr work = 16/24 = 2/3. Remaining work = 1 – 2/3 = 1/3. Using work and time formula: This will be completed in 1/3 × 18 i.e. 6 hrs. So, total time taken to complete work = 16 + 6 = 22 hrs.
Question 6
A can do a piece of work in 10 days, and B can do this work in 15 days. 
They both started together. After three days, B left the work. 
In how many more days will the work be finished?
A
5 days
B
10 days
C
15 days
D
20 days
Question 6 Explanation: 
Their combined 3 day work = 3(1/10 + 1/15) = 3/6 = 1/2. Remaining work = 1 – 1/2 = ½. This will be done by A in 1/2 × 10 = 5 days.
Question 7
A can do a piece of work in 12 days. B can do this work in 16 days. 
A started the work alone. After how many days should B join him, 
so that the work is finished in 9 days?
A
2 days
B
3 days
C
4 days
D
5 days
Question 7 Explanation: 
A’s work in 9 days = 9/12 = 3/4. Remaining work = 1/4. This work was done by B in 1/4 × 16 = 4 days. ∴ B would have joined A after 9 – 4 = 5 days.
Question 8
A and B can do a piece of work in 4 days, while C and D can 
do the same work in 12 days. In how many days will A, B, C and 
D do it together?
A
12 days
B
4 days
C
3 days
D
2 days
Question 8 Explanation: 
A, B, C and D will together take ¼ + 1/12 = = 4/12 = 1/3 ⇒ 3 days to complete the work.
Question 9
A, B, C, and D can do a piece of work in 20 days. If A and B can 
do it together in 50 days, and C alone in 60 days, 
find the time in which D alone can do it.
A
120 days
B
200 days
C
75 days
D
90 days
Question 9 Explanation: 
D alone will take 1/20 – 1/50 – 1/60 = 4/300 = 1/75 ⇒ 75 days to complete the work.
Question 10
12 men can complete a work in 8 days. 16 women can complete the 
same work in 12 days. 8 men and 8 women started working and 
worked for 6 days. How many more men are to be added to 
complete the remaining work in 1 day?
A
8
B
12
C
16
D
25
Question 10 Explanation: 
1 man 1 day work =1/96 1 woman 1 day work = 1/192 Work done in 6 days=6(8/96+8/192) = 6×18 =3/4 Remaining work = 1/4 (8 men +8 women)’s 1 day work = 1(8/96+8/192) =1/8 Remaining work =1/4 – 1/8 = 1/8 1/96 work is done in 1 day by 1 man Therefore, 1/8 work will be done in 1 day by 96 x (1/8) =12 men
There are 10 questions to complete.
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