Question

Tommy types 54 words per minute, with an average of 3 mistakes. How many mistakes would you expect Tommy to make if he typed 300 words?

Answer 1

X = mistakes in 300 words

54/3 = 300/X

54X = 3 x 300

X = 900/ 54

X = about 17 words, since 16 and 2/3 rounded to the nearest tenth is 17

Answer 2

around 17 mistakes

Explanation:

We can write a ratio to solve

54 words 300 words

------------------ = -------------------

3 mistakes x mistakes

Using cross products

54x = 3*300

54x = 900

Divide by 54

54x/54 = 900/54

x =50/3

x = 16.66666666(repeating)

around 17 mistakes