How long in years does it take to grow 0.30 m ? Note: 1 yr.= 3.156 x 100000000 s.?

Question

Carole's hair grows with an average speed of 3.5 x 0.00000001 m/s. How long in years does it take her hair to grow 0.30 m?

Answer 1

t = x/v = 0.3 m/0.000000035 m/s = 8571429 s = 0.27159 yr.
Note 1 yr = 0.1 * the number you gave.

Answer 2

v=0.000000035m/s
x=v*t
t=v/x=0.000000035m/s/0.3m
t=1.1666666666666666666666666666667e-7 s *1 year/(3600*24*365)
t= 3.6994757314392017588364620328091e-15 years