Question

the scale of a map says that 4 centimeters represents 5 km what is the actual number of kilometers that is represented by 16 cm on the map

Answer 1

This question is about proportions. So we can build the following table:

Centimeters Km

4 5

16 x

So we have the following equation

$\frac{4}{5}=\text{ }\frac{16}{x}$

this equation is equivalent to

$\frac{x}{16}\text{ = }\frac{5}{4}$

So multyplying by 16 on both sides we get

$x\text{ = }\frac{16\cdot5}{4}\text{ = 4}\cdot5\text{ = 20}$

So 16 cm are 20 km.