How to convert three and one half feet into inches? ?

Christina can paint 420 square feet in 105 minutes. which unit rate describes the scenario?

Expresa commuter train leaves downtown sation and travels at a average speed of 55 miles per hour towards the north side sation, which is 50miles away. thirty minutes later, express commuter train #7 leaves north side and travels at a average speed of 35miles per hour towards downtown sation. at the moment the two trains pass each other, how far(in miles) is train #12 from the downtown sation and how long(in minutes) has the #12 train been traveling

Given the following linear function sketch the graph of the function and find the domain and range. ƒ(x) = -5x + 4