Question

A cell phone is 86 mm long and 30 mm wide. What is the ratio of the width to the length?

Answer 1

Ratio of width : length `-> 15:41`

Explanation:

width : length `-> 30 : 86`

This may also be presented as

`("width")/("Length") -> 30/86" "` Note that this is NOT a fraction

However, the proportioning behaves like a fraction in that the top value always has the same ratio to the bottom value.

`(30-:2)/(86-:2) =15/43`

43 is a prime number so this ratio cannot be simplified any further.

So ratio width : length `-> 15:43`

Answer 2

The width : the length is
`" "15" : "43`

Explanation:

A ratio is a comparison between two or more quantities.
A ratio:

• is always in the simplest form
• does not have fractions
• does not have decimals
• does not have units ( but they must be the same)

The ratio of the width to the length of the cell phone is:

`" "30" : "86" "larr` both are given in mm
`" "15" : "43" "larr` simplest form (divided by 2)

This means that for every `15`mm of the width there will be `43`mm in the length