Maths! Simplifying ratios as fractions?

[KPeh]

Hi

If I have a ratio which isn't straightforward, how can I figure out how to simplify it (or conversely, what the highest common multiple is)?

Eg: 152:121.6:212.8

The highest common multiple is 30.4, so it goes down to 5:4:7. But how do you figure that out? I was once told how to do this by converting them to fractions (I think, top heavy), but I've forgotten how.

Can anyone help? Thanks!

 

[KPeh]

I'd just multiply each by 10 to give:

1520:1216:2128

then cancel down which leaves the figure you mentioned.

Thanks, but that takes much too long - it's for a timed numerical reasoning exam (which I'm doing tomorrow...). Sadly the person who explained how to do it quickly originally to me is off on holiday atm..!

 

[KPeh]

Thanks titanium, but that's still not what I'm looking for. That was basically what I did find on google/youtube.

But you're right - I did mean highest common factor. Actually, that's not too important, the ratio just needs to be in its simplest form (and quickly) for the purposes of the exam.

Thanks