Question

To convert centimeters to kilometers, which conversion factors would you need?

Answer 1

Answer:

The last option is the only correct one if you like to multiply

The second last option is good if you like to divide.

Explanation:

Each fraction in the last two options has a value of 1

example

dividing by 1

15 cm /(100 cm/ 1 m) = 0.15 m          0.15 m / (1000 m/ 1km) = 0.00015 km

and

multiplying by 1

15 cm(1 m / 100cm) = 0.15 m         0.15m(1 km/1000m) = 0.00015 km

only one of the two fractions in each of the top two options has a value of 1.