Lots of points math a few questions

Marcus built a model car that is 4 inches wide. what scale was used to build the car if the actual width of the car is 6 feet? a. 1 in. = 2 ftb. 1 in. = 2.5 ftc. 1 in. = 1.5 ftd. 1 ft = 1.5 in.

Which speed is the fastest (use 1 mile ≈ 1.6 kilometers)? a. 12 miles/hour b. 18 feet/second c. 19 kilometers/hour d. cannot be determined

A6 ounce bottle of dressing costs $1.56 a 14 ounce bottle costs $3.36 a 20 ounce bottle costs $5.60 which has the lowest cost per ounce