Susan can type 10 pages in 5 minutes. Mary can type 5 pages in 10 minutes. Working together, how many pages can they type in 30 minutes?A. 15B. 20C. 65D. 75

Sandeep Jindal

• Jun 30th, 2005

Susan = 10*6
Mary = 5*3
Total = 60+15= 75

Bhoomika sharma Profile Answers by Bhoomika sharma Questions by Bhoomika sharma

• Dec 26th, 2008

Susan, does one page:

(5/10)=1/2

Mary, does one page:

(10/5)=2

so, both do :

net-work: (2+1/2)=5/2

thus ,

1 minute work done: 5/2

so,,in 30-minutes :  30*(5/2)=75 pages

• Feb 11th, 2009

Susan can type pages in 5 min=10
in 1 min=2
in 30 min=60
Mary can type pages in 10 min=5 pages
in 1 min=1/2
in 30 min=15 pages
so when working together they can type=60+15
=75 pages

• Jul 10th, 2010

Let "x" as the total number of pages both can type in 30 minutes.
10/5 + 5/10 = x/30
We can't add 10/5 and 5/10 since they have different denominator. LCD is 10, we need to multiply 10/5 by 2 to make it 20/10.
20/10 + 5/10 = x/30
We can now add the fractions.
25/10 = x/30
To get the value of "x" we need to cross multiply 10*x  and 25*30 would result.
10x = 750
To get the value of "x" divide 750 by 10
x=750/10
x= 75.

shanker

• Jul 29th, 2015

75

ZINABU

• Mar 28th, 2018

STEP1: write the ratio:10/5+5/10=x/30
STEP2: use the LCD number
the LCD number for this is 10
step3: 10*2/10 +5/10=x/30
20/10+5/10=x/30
25/10=x/30
25*30=x*10
x=750/10
=75