A girl asks her father how many ties he has and he answers with a riddle: "Seven-eighths of my ties plus six." How many ties does her father have?

The father has a total of 48 ties

You can make a linear equation to solve. Let x be the number of ties he has. / frac{7x}{8} + 6 = x is the same as the problem given. Subtract / frac{7x}{8} on both sides to get 6 = / frac{x}{8}, and by multiplying 8 on both sides we get x = 48. The father then has 48 ties.