Jack typed 80 words per minute when he enrolled in a typing course. His typing speed increased by 3% two weeks into the course. At the end of the course, Jack was able to type his entire 1,680 word document in 20 minutes.

What was the percent of increase in his typing speed from the beginning of the course to the end?

2 answers

1680wd/20min = 84wd/min

84/80 = 1.05 or a 5% increase in speed.
At the office supply store, a box of 25 pens costs R7.19, a box of 50 pens costs R10.78, a box of 75 pens costs R14.53, a box of 100 pens costs R22.50, and a box of 125 pens costs R26.25. Which box has the cheapest per pen cost?