A franchise is owned by three people. The first owns one fifth of the business and the second owns three sevenths of the business. What fractional part of the business is owned by the third​ person?

Answer 1

The total must = 1 Let x = the unknown fraction

Then

1/5 + 3/7 + x = 1 or 7/35 + 15/35 + x = 35/35

or

22/35 + x = 35/35 or x = 35/35 - 22/35 = 13/35

So, the third person owns 13/35 of the business!