Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 10)
10.
A machine P can print one lakh books in 8 hours, machine Q can print the same number of books in 10 hours while machine R can print them in 12 hours. All the machines are started at 9 A.M. while machine P is closed at 11 A.M. and the remaining two machines complete work. Approximately at what time will the work (to print one lakh books) be finished ?
Answer: Option
Explanation:
| (P + Q + R)'s 1 hour's work = |  |
1 | + | 1 | + | 1 |  |
= | 37 | . |
| 8 | 10 | 12 | 120 |
| Work done by P, Q and R in 2 hours = | |
37 | x 2 | |
= | 37 | . |
| 120 | 60 |
| Remaining work = | |
1 - | 37 | |
= | 23 | . |
| 60 | 60 |
| (Q + R)'s 1 hour's work = | |
1 | + | 1 | |
= | 11 | . |
| 10 | 12 | 60 |
| Now, | 11 | work is done by Q and R in 1 hour. |
| 60 |
| So, | 23 | work will be done by Q and R in | |
60 | x | 23 | |
= | 23 | hours  2 hours. |
| 60 | 11 | 60 | 11 |
So, the work will be finished approximately 2 hours after 11 A.M., i.e., around 1 P.M.
Discussion:
95 comments Page 6 of 10.
Piyus said:
1 decade ago
Friends
P's 2 hr work = 1/8*2=1/4
rest 3/4 work done by q&r
q+r 1hr = 1/10 + 1/12=11/60 work
3/4 work by q&r=60/11 * 3/4=4.09
The work complete time was 9a.m+4=1p.m
P's 2 hr work = 1/8*2=1/4
rest 3/4 work done by q&r
q+r 1hr = 1/10 + 1/12=11/60 work
3/4 work by q&r=60/11 * 3/4=4.09
The work complete time was 9a.m+4=1p.m
Janie said:
5 years ago
The solution is;
10 - 8=2
12 - 10=2
So, two is a common difference.
Then, P is closed at 11:AM.
11:00 + 00:30 = 11:30.
Continued for four good times then you'll get 1:00PM.
10 - 8=2
12 - 10=2
So, two is a common difference.
Then, P is closed at 11:AM.
11:00 + 00:30 = 11:30.
Continued for four good times then you'll get 1:00PM.
Sameer said:
1 decade ago
P 1hrs work 1/8
Q 1hrs work 1/10
R 1hrs work 1/12
p worked for 2 hrs so 2*1/8
suppose Q and r worked for 'x' hrs
then,
2*1/8+(1/10)*x+(1/12)x = 1
x=4.09
ans 9+4.09 = 1pm
Q 1hrs work 1/10
R 1hrs work 1/12
p worked for 2 hrs so 2*1/8
suppose Q and r worked for 'x' hrs
then,
2*1/8+(1/10)*x+(1/12)x = 1
x=4.09
ans 9+4.09 = 1pm
(1)
Ramkumar said:
1 decade ago
Can anyone tell
Why you put last step as 9am+4?
Already p, q, r done by 2hrs and (q&r) in 4 hrs know.
Then 2+4=6 only know.
On this step I am in confusion. Help me.
Why you put last step as 9am+4?
Already p, q, r done by 2hrs and (q&r) in 4 hrs know.
Then 2+4=6 only know.
On this step I am in confusion. Help me.
Deepak said:
1 decade ago
A and B can done a work in 10 days, B and C done same work in 18 days,
If A did work 4 days, B did 8 days and C did 14 days. How much days C takes to complete same work?
If A did work 4 days, B did 8 days and C did 14 days. How much days C takes to complete same work?
Ashna said:
1 decade ago
P in 1 hr-----1/8.
Q in 1 hr-----1/10.
R in 1 hr-----1/12.
Therefore 2/8+(x+2)/10+(x+2)/12 = 1.
On solving x=23/11=2 hrs. (approx).
Therefore, 11 A.M.+2hr = 1 P.M.
Q in 1 hr-----1/10.
R in 1 hr-----1/12.
Therefore 2/8+(x+2)/10+(x+2)/12 = 1.
On solving x=23/11=2 hrs. (approx).
Therefore, 11 A.M.+2hr = 1 P.M.
Balu said:
10 years ago
Hello guys, easy solution:
X-2/8 + X/10 + X/12 = 1 (lik A+B+C's 1 Day Work).
By solving we get X = 4.
So, Machines are started at 9.
= 9+4 = 13 (i.e, 1'O clock).
X-2/8 + X/10 + X/12 = 1 (lik A+B+C's 1 Day Work).
By solving we get X = 4.
So, Machines are started at 9.
= 9+4 = 13 (i.e, 1'O clock).
Div said:
1 decade ago
Since machine p stops after 37 units of work is completed from 60 units of work, still (60-37=23) 23units of work is remaining. hence, 1-(37/60)= 23/60
Jyothi.k said:
1 decade ago
@Sowjanya
11/60 work done by q and r in i hour
Therefore
1 work done by q and r in 60/11 hour
So 23/60 work done by q and r in 60/11*23/60 hours
11/60 work done by q and r in i hour
Therefore
1 work done by q and r in 60/11 hour
So 23/60 work done by q and r in 60/11*23/60 hours
K.anusha said:
1 decade ago
Please I can't get the answer this last step please friends will explain to me.
How will come to this is 3/4 can you explain to me friends please.
How will come to this is 3/4 can you explain to me friends please.
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