Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 18)
18.
Ravi and Kumar are working on an assignment. Ravi takes 6 hours to type 32 pages on a computer, while Kumar takes 5 hours to type 40 pages. How much time will they take, working together on two different computers to type an assignment of 110 pages?
Answer: Option
Explanation:
| Number of pages typed by Ravi in 1 hour = | 32 | = | 16 | . |
| 6 | 3 |
| Number of pages typed by Kumar in 1 hour = | 40 | = 8. |
| 5 |
| Number of pages typed by both in 1 hour = |  |
16 | + 8 |  |
= | 40 | . |
| 3 | 3 |
 Time taken by both to type 110 pages = |
|
110 x | 3 | |
hours |
| 40 |
| = 8 | 1 | hours (or) 8 hours 15 minutes. |
| 4 |
Discussion:
53 comments Page 5 of 6.
Sumit Vyas said:
1 decade ago
(16/3+8) = 40/3 how can simplify this equation?
Amansamana said:
1 decade ago
Hey guys why should direct count total unit, like,
Ravi 6* 32 = 192.
And kumar unit 5 * 40 = 200. But solving by that answer will be approximately 9, so anybody can tell, what is the mistake in that method?
Ravi 6* 32 = 192.
And kumar unit 5 * 40 = 200. But solving by that answer will be approximately 9, so anybody can tell, what is the mistake in that method?
Kishore said:
1 decade ago
@Krittika.
Your method is not correct. It can be explain with a simple example.
Suppose ravi type 1 page in 1 hr.
Kumar type type 1 page in 1.5 hr.
If they work together, 1 page type by both can not be 1+1.5 = 2.5 hr (combined effort should reduce the time but here its opposite).
I hope you get it.
Your method is not correct. It can be explain with a simple example.
Suppose ravi type 1 page in 1 hr.
Kumar type type 1 page in 1.5 hr.
If they work together, 1 page type by both can not be 1+1.5 = 2.5 hr (combined effort should reduce the time but here its opposite).
I hope you get it.
Sunny said:
1 decade ago
I did the following steps but the answer I am getting is 8.25:
Ravi takes 6 hrs to type 32 pages.
For one hour he will type:32/6=16/3 pages.
Kumar takes 5 hrs to type 40 pages.
For one hour he will type:40/5=8 pages.
So,for one hour kumar and ravi type (16/3+5) pages i.e. 40/3.
1 hour---40/3 pages.
? ---110 pages.
Do cross multiplication and you will get answer.
Ravi takes 6 hrs to type 32 pages.
For one hour he will type:32/6=16/3 pages.
Kumar takes 5 hrs to type 40 pages.
For one hour he will type:40/5=8 pages.
So,for one hour kumar and ravi type (16/3+5) pages i.e. 40/3.
1 hour---40/3 pages.
? ---110 pages.
Do cross multiplication and you will get answer.
Nitin. said:
1 decade ago
If you solve 110*3/40 you will get exactly 8.25. Then why 8.15 please anyone explain in detail.
Krittika said:
1 decade ago
Why can't I do like this?
32 pages r typed by Ravi in 6 hrs
1 page is typed in 6/32=3/16 hrs.
similarly 1 page typed by kumar is 1/8 hrs.
then 1 page typed by both of them in (3/16+1/8)=5/16 hrs.
So 110 pages typed by them in 110 * 5/16 hrs = !!?
32 pages r typed by Ravi in 6 hrs
1 page is typed in 6/32=3/16 hrs.
similarly 1 page typed by kumar is 1/8 hrs.
then 1 page typed by both of them in (3/16+1/8)=5/16 hrs.
So 110 pages typed by them in 110 * 5/16 hrs = !!?
Kunu said:
1 decade ago
@Navena
16/3+8=
16+24/3= 40/3(LCM 3)
16/3+8=
16+24/3= 40/3(LCM 3)
Navena said:
1 decade ago
How do you solve 16/3+8 ?
Ashwin said:
1 decade ago
No of pages typed/Hours=40/3/1=40/3-----First case
No of pages typed/Hours=110/x-----------second case
The ratio would be same in both the cases
40/3=110/x
Therefore
x=110*3/40=8*1/4 hrs
No of pages typed/Hours=110/x-----------second case
The ratio would be same in both the cases
40/3=110/x
Therefore
x=110*3/40=8*1/4 hrs
Ramu said:
1 decade ago
Why did they change 40/3 into 3/40 in the next line. ?
They could have done like 110*(40/3) itself. !
They could have done like 110*(40/3) itself. !
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