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?
7 hours 30 minutes
8 hours
8 hours 15 minutes
8 hours 25 minutes
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

Therefore 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 1 of 6.

Pandu said:   1 decade ago
How to calculate the 8 1/4 hours= 8 hours 15 minutes.

Mahesh said:   1 decade ago
1 hour mean 60 minutes
1/4 hour mean 15 minutes
1/2 hour = 30 minutes

Mani said:   1 decade ago
33/4

8.25

0.25 *60 = 15

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. !

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

Navena said:   1 decade ago
How do you solve 16/3+8 ?

Kunu said:   1 decade ago
@Navena
16/3+8=
16+24/3= 40/3(LCM 3)

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 = !!?

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.

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.


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