Daniel W. answered • 03/15/15
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Retired Navy Providing Basic Math and Test Prep Tutoring
Hello Marc!
The first thing we need to do is find the least common denominator (LCD) for the two fractions. That would be 40, because both 8 and 10 are factors of the number 40. 3/8 will become 15/40 (multiply both numerator and denominator by 5) and 3/10 will become 12/40 (multiply by 10).
15/40 - 12/40= 3/40
He ran 3/40 of a mile farther on Friday.
