SOLUTION: Connie can type 600 words in 5 minutes less than it takes Katie to type 600 words. If Connie types at a rate of 20 words per minute faster than Katie types, find the rate of each w

Question 171115: Connie can type 600 words in 5 minutes less than it takes Katie to type 600 words. If Connie types at a rate of 20 words per minute faster than Katie types, find the rate of each woman.

I need help please!
Answer by Mathtut(3670) (Show Source): You can put this solution on YOUR website!
lets call kates time t and her rate r
lets call connies time t-5 and her rate r+20
words typed are equal.
:
600=rt.......eq 1
600=(r+20)(t-5)..eq 2
:
lets rewrite eq 1...t=600/r and plug that value into eq 2
:
---->...multiply by r
:
--->
:
divide by 5

:
throw out the negative number
:
so WPM kates typing speed
:WPM connies typing speed

:

Solved by pluggable solver: SOLVE quadratic equation with variable

Quadratic equation (in our case ) has the following solutons:

For these solutions to exist, the discriminant should not be a negative number.

First, we need to compute the discriminant : .

Discriminant d=10000 is greater than zero. That means that there are two solutions: .

Quadratic expression can be factored:

Again, the answer is: 40, -60. Here's your graph:

RELATED QUESTIONS
Connie can type 600 words in 5 minutes less than it takes Katie to type 600 words. If... (answered by MathLover1,Edwin McCravy)

Connie can type 600 words in 5 minutes less than it takes katie to type 600 words. If... (answered by stanbon)

[Johnny can type 600 words in 8 minutes. In how many minutes can he type 2100... (answered by TimothyLamb)

Tiffany can type 280 words in 5 minutes At this rate how long will it take her to... (answered by macston)

If a writer types 675 words in 9 minutes how many words can he type in 13... (answered by ikleyn)

Michael types 250 words in 20 minutes. How many hours will it take him to type 7500... (answered by ikleyn,VFBundy)

Rolando can type 1,320 words in 24 minutes. At this rate, how many minutes should it take (answered by stanbon)

Stephen can type 180 words in 4.5 minutes at this rate how many minutes will it take... (answered by ikleyn)

Jake can type 120 words in 100 seconds and Kevin can type 110 words in 2 minutes. at that (answered by macston)