a. 1 inch = 25,4 mm
b. 456 mm = 45,6 cm divisé par 2,54cm = 17,95 inches
c. 1 foot = 12inches x 2,54cm = 30,48 cm
d. 15 miles = 15 miles x 1760 yards x 3 foots = 79 200 foots
e. 128 inch = 128 : (3x12) = 3,55
f. 30 miles = 2,54cm x 12 inches x 3 foots x 1760 yards x 30 miles = 4 828 032 cm = 48,28032 km
