Question

Tess has 42 words of an essay typed and is typing about 1.3 words per second. Margo 122 words of an essay typed and is erasing about 1.2 words per second. In how many seconds will the number of words in Tess’s essay exceed the number of words in Margos essay?

Answer 1

32 seconds

Explanation:

For some number of seconds (s), Tess's essay length (t) will be ...

t = 42 +1.3s

and Margo's essay length (m) will be ...

m = 122 -1.2s

We will have t > m when ...

t > m

42 +1.3s > 122 -1.2s

2.5s > 80 . . . . . . . . add 1.2s-42

s > 32 . . . . . . . . . . . divide by 2.5

After 32 seconds, Tess's essay will exceed Margo's in length.