### Home > A2C > Chapter 8 > Lesson 8.2.2 > Problem 8-131

8-131.

The average cost of movie tickets is $9.50. If the cost is increasing 4% per year, in how many years will the cost double? Homework Help ✎

Construct a representation of this scenario using the generic exponential equation:*y* = *ab ^{x}*

Solve for *x* (the number of years):

2(9.50) = 9.50(1.04)^{x}

≈ 17.67 years