What number is a factor of 15 but not a multiple of 3?

Solve with work both bert and ernie received an increase in their weekly salaries. bert's salary increased from $520 to $520. ernie's salary went from $580 to $645. find the percent of increase for each salary. what was the larger of the two percents ?

Which one ? is the answer and how to find this answer

Julie was able to walk 16 km through the zoo in 6 hours. how long will it take her to walk 24 km through the zoo?