Answer:
5 hours
Explanation:
Let x represent the number of hours London works landscaping.
We can set up the following system of equations to represent the information given in the problem:
24x + 10(15 - x) = 220
24x + 150 - 10x = 220
14x = 70
x = 5
London must work a minimum of 5 hours landscaping to meet her requirements.