Respuesta :

Answer:

50 km

Step-by-step explanation:

Given

[tex]r = 4cm : 20km[/tex] -- Scale ratio

Required

Actual representation of 10cm

Let the actual measurement be x.

So, we have:

[tex]r =10cm:x[/tex]

Equate both value s of r

[tex]10cm : x = 4cm : 20km[/tex]

Express as fraction

[tex]\frac{x}{10cm } =\frac{20km}{4cm}[/tex]

Multiply by 10cm

[tex]10cm * \frac{x}{10cm } =\frac{20km}{4cm} *10cm[/tex]

[tex]x =\frac{20km}{4} *10[/tex]

[tex]x =5km *10[/tex]

[tex]x =50\ km[/tex]