Section: Mathematics Usage

12) Jane can mow a lawn in 2 hours. Henry can mow the same lawn in 1.5 hours. About how long will it take to mow the lawn if Jane and Henry worked together?

1. 28 minutes
2. 42 minutes
3. 51 minutes
4. 1.2 hours
5. 1.5 hours

To solve this equation change the hours to minutes and set up the following equations.

x/120 + x/90 = 1

Next find the least common denominator which in this case is 360.

Multiply by 360. 3x + 4x = 360, so x = 51.