Question

a car takes 8 s to increase its velocity from 10 m/s to 30 m/s. What is its average accelleration?

Answer 1

a= v-u/t
  = 30-10/8
= 2.5 m/s

Answer 2

a=(v-u)/t
a=(30-10)/8
a=20/8
a=2.5m/s²