The ":" is actually a division, a fraction.
So part a is therefore,
[tex]\dfrac{w}{100}=\dfrac{12}{25}[/tex]
Here we use cross multiplication,
[tex]\dfrac{a}{b}=\dfrac{c}{d}\Longleftrightarrow ad=bc[/tex]
And we have,
[tex]
25w=12\cdot100 \\
w=\dfrac{12\cdot100}{25}=\dfrac{1200}{25}=\boxed{48}
[/tex]
Now part b.
First convert 2m to cm. 1m = 100cm therefore 2m is 200cm.
Now we have simplified to,
[tex]\dfrac{180}{200}=\dfrac{1.8}{2}=\dfrac{\dfrac{18}{10}}{2}=\dfrac{\dfrac{9}{5}}{2}=\boxed{\dfrac{9}{10}=9:10}
[/tex]
Hope this helps.
r3t40
