Express 15$ for 10 gallons as a unit rate

You are remodeling your kitchen. you’ve contacted two tiling companies who gladly told you how long it took their workers to tile of a similar size jim completed half the floor in 8 hours. pete completed half of the other floor in 7 hours. if pete can lay 20 more tiles per hour than jim, at what rate can jim lay tiles

What numbers are included in the set of integers? what numbers are not included?

Indicate the formula for the following conditions: p^c(n,r)=