A ball rolls at a speed of 4 km/h toward the back of a bus traveling forward at a speed of 35 km/h. What is the magnitude of the ball’s velocity relative to the ground? *

i had this question and the answer was 3.15 miles.

martina travels from school to her mom's office. from there, she walks to school. after school, she walks to the library and then to a friends house before finally ending back at home. find martina's total distance traveled.

a) 0 miles  

b) 0.4 miles  

c) 1 mile  

d) 3.15 miles