Starting with the definition 1 in. = 2.54 cm, find the number of (a) kilometers in 1.00 mile and (b) feet in 1.00 km.

Solution 1E Step 1 a) 1 inch = 2.54 cm 12 inch = 1 foot = 12 × 2.54 cm = 30.48 cm 3 foot = 1 yard = 3 × 30.48 cm = 91.44 cm 220 yard = 1 furlong = 220 × 91.44 cm = 20116.8 cm 8 furlong = 1 mile = 8 × 20116.8 cm = 160934.4 cm We know that, 1 m = 100 cm Or, 1 cm = (1/ 100) m Therefore, 1 mile = 160934.4 ×(1 / 100) m = 1609.34 m 1 km = 1000 m Therefore, 1 m = (1/1000) km That is, 1 mile = 1609.34 × (1/ 1000) km = 1.61 km