SOLUTION: Jose types 60 words per minute and Vishna types 40 words per minute. They each type one half of an article. In words per minute, what was the rate at which the entire article was t

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Jose types 60 words per minute and Vishna types 40 words per minute. They each type one half of an article. In words per minute, what was the rate at which the entire article was t      Log On


   



Question 175289: Jose types 60 words per minute and Vishna types 40 words per minute. They each type one half of an article. In words per minute, what was the rate at which the entire article was typed?
What I did was I just averaged both rates which equaled 50,but the right answer is 48 WPM

Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Ok, on this type of problem, you need to use the concept of weighted averages.
Let's say that there are x words in the article being type-written.
Now Jose, typing at 60 wpm, would take %28x%2F2%29%2F60+=+x%2F120 minutes to type half the article while Vishna, typing at 40 wpm would take %28x%2F2%29%2F40+=+x%2F80 minutes to type half the article. Adding these two rates, we get:
%28x%2F120%29%2B%28x%2F80%29+=+5x%2F240 which reduces to:
x%2F48 so the combined typing speed to type the article is 48 words per minutes.