Question

Suppose a man’s scalp hair grows at a rate of 0.35 mm per day. What

Answer 1

1cm = 10mm
1 inch = 2.54 cm
1ft = 12 inch
(0.35 mm / day) * (1 cm / 10 mm) * (1 in / 2.54 cm) * (1 ft / 12 in) =
0.001148... ft/day 
Now converting days into centuries:
1 year = 365 days
1 century = 100 year
(0.001148 ft / day) * (365 day / 1 yr) * (100 yr / 1 cent)
= 41.9 ft/century