Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 24 May 2013, 08:28

# Working together, John and Jack can type 20 pages in one

Author Message
TAGS:
VP
Joined: 22 Nov 2007
Posts: 1108
Followers: 6

Kudos [?]: 80 [0], given: 0

Working together, John and Jack can type 20 pages in one [#permalink]  17 Feb 2008, 06:37
Working together, John and Jack can type 20 pages in one hour. They will be able to type 22 pages in one hour if Jack increases his typing speed by 25%. What is the ratio of Jack's normal typing speed to that of John?

1/3

2/5

1/2

2/3

3/5
Manager
Joined: 02 Jan 2008
Posts: 162
Followers: 1

Kudos [?]: 34 [0], given: 0

Re: work [#permalink]  17 Feb 2008, 07:29
D
--
Jack: x pages/hr, John: y pages/hr

x/20 + y/20 = 1 = 1.25x/22 + y/22
x:y=2:3
SVP
Joined: 28 Dec 2005
Posts: 1612
Followers: 1

Kudos [?]: 53 [0], given: 2

Re: work [#permalink]  17 Feb 2008, 08:14
D for me as well.

let a =jacks rate, and b=johns rate

a+b=20

1.25a+b=22

0.25a=2 -->a=8 -->b=12

a/b=8/12=2/3
VP
Joined: 22 Nov 2007
Posts: 1108
Followers: 6

Kudos [?]: 80 [0], given: 0

Re: work [#permalink]  17 Feb 2008, 10:19
pmenon wrote:
D for me as well.

let a =jacks rate, and b=johns rate

a+b=20

1.25a+b=22

0.25a=2 -->a=8 -->b=12

a/b=8/12=2/3

oa is d. in this case we use the formula:

time necessary for Jack + time necessary for John = total time

let's consider the formula 1/x + 1/y = total time or xy/(x+y)=total time

in this case we already have the two times: 1/x and 1/y, which are a and b.

is that right? I encounter many problems in approaching work questions.
Re: work   [#permalink] 17 Feb 2008, 10:19
Similar topics Replies Last post
Similar
Topics:
3 typists working together can type 36 pages in 30 minutes. 5 07 Dec 2005, 07:29
1 working together, John and Jack can type 20 pages in 1hr. If 3 11 Jun 2007, 20:54
3 secretaries working together can type 36 pages of text in 1 18 Oct 2007, 10:40
8 It takes Jack 2 more hours than Tom to type 20 pages. If 17 07 Oct 2010, 10:49
2 Working together, John and Jack can type 20 pages in one hou 6 09 Oct 2010, 01:26
Display posts from previous: Sort by