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

is this growth rate in feet per century?

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