Question

Ken calculates that he spends 15% of a school day in science class. If he spends 75 minutes in science class, how

many minutes does Ken spend in school?

Answer 1

500 minutes

Explanation:

Let x be the time Ken spends in school. [I'll note that x < infinity, a common misperception.]

Kevin spends 15% of his school time in science class. That would be expressed as 0.15x.

We learn that Science class lasts 15 minutes, so we can write:

0.15x = 75 minutes

x = (75 minutes)/0.15

x = 500 minutes is the time Kevin spends in school

=================

(500 minutes)*(1 hr/60 minutes) = 8 1/3 hours