Answer: Jim can lay 25 tiles per hour.
Explanation:
Let be "x" Jim's rate and "y" Pete's rate.
We know that Jim completed half the floor in 4 hours, then:
![4x](https://img.qammunity.org/2020/formulas/mathematics/high-school/mn8feglp5shfkjwjpn7fx7q0hz2xwiqh4j.png)
And Pete completed the other half of the floor in 2 hours, then:
![2y](https://img.qammunity.org/2020/formulas/mathematics/college/dez1jkkzqxpt8h9vxve3jdqnkub6xzorb3.png)
Since Jim completed half the floor and Pete completed the other half:
[Equation 1]
We also know that Pete can lay 25 more tiles per hour than Jim, then:
[Equation 2]
Then, we can substitute Equation 2 into Equation 1 and solve for "x":
![4x=2(x+25)\\\\4x=2x+50\\\\4x-2x=50\\\\x=(50)/(2)\\\\x=25](https://img.qammunity.org/2020/formulas/mathematics/middle-school/og2pqlkgvd68vdhdzrl2815o89e89o04mu.png)
Therefore, Jim can lay 25 tiles per hour.