What is the percent of change in the cost of a hot dog

How do i do this? i don’t understand

Abus travels 36 miles in 45 minutes. enter the number of miles the bus travels in 60 minutes at this rate.

Rob spent 25%, percent more time on his research project than he had planned. he spent an extra h hours on the project. which of the following expressions could represent the number of hours rob actually spent on the project? two answers