Question

Which proportion would you use to solve the following problem?

A map has a scale of 1 cm : 5 km. Determine how far apart two cities are if they are 4 cm apart on the map.

Answer 1

• Let the two cities are x km far apart.
• 1cm is equal to 5km
• Distance on map 4cm

Now

`\\ \sf\longmapsto (1)/(4)=(5)/(x)`

• Cross multiply

`\\ \sf\longmapsto (1)/(5)=(4)/(x)`

Option A is correct

Answer 2

• A) 1/5 = 4/x

Explanation:

The scale is:

• 1 cm : 5 km

Given:

• 1 cm ⇒ 5 km
• 4 cm ⇒ x km

Converted to ratio it is:

• 1/5 = 4/x

Correct choice is A