How can you find the thickness of a bottom of a hollow cylinder by using vernier calliper

attach the statements so i can answer : )

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

snell's law

refractve index = sin incidence / sin refraction