Question

A library has 167 trees on their property, but they are having trouble growing grass so they need to pay to have trees cut down each year until the property has less than 50 trees. If they can pay to have only four trees cut down this year, but eight trees cut down every year after that, in how many years will they have less than 50 trees on their property?

Answer 1

15 years

Explanation:

Given:

• Number of trees = 167
• This year limit = 4 trees
• Yearly limit following years = 6 trees per year
• Target number of trees = 50

Building inequality:

• 167 - 4 - 8x < 50
• 8x > 113
• x > 113/8
• x > 14.125

Adding current year to 14 we get 15 years as answer