The Student Room Group
Uni students - Complete our survey >>
Uni students - Complete our survey >>
Uni students - Complete our survey >>

simplifying ratios

Does anyone know how to simplify 152:121.6:212.8 to 5 4 7? It's been a long time since I have done ratios.

I multiplied it 10, then kept dividing by 2 until I got 95 76 133 then noticed a 19 difference between 95 and 76. I'm sure there is a more feasible way to tackle this..?
(edited 9 years ago)
Original post by loloway
Does anyone know how to simplify 152:121.6:212.8 to 5:4:7? It's been a long time since I have done ratios.

I multiplied it 10, then kept dividing by 2 until I got 95:76:133 then noticed a 19 difference between 95 and 76. I'm sure there is a more feasible way to tackle this..?


Knowing what your target is helps as 95/5 = 19, and so that's the factor to divide by to get to your desired result.

If you don't know the target, then if it's not obvious with a little trial and error, then a foolproof method would be to, multiply through until you have all integers (assuming that can be done), then apply the Euclidean algorithm a couple of times, but it's a massive overkill.

Find the HCF of your first two scaled number, and then the HCF of this with the third number. The result is the HCF of all three. Divide by that to get the ratio in its lowest integer terms.
Original post by loloway
Does anyone know how to simplify 152:121.6:212.8 to 5 4 7? It's been a long time since I have done ratios.

I multiplied it 10, then kept dividing by 2 until I got 95 76 133 then noticed a 19 difference between 95 and 76. I'm sure there is a more feasible way to tackle this..?


Were you simply asked to show the result?

If so, note that 152÷5=30.4152 \div 5 = 30.4

Carry out two more divisions.
(edited 9 years ago)
Reply 3
Avatar for loloway
loloway
OP
9
No it was not given. This question is from a Psychometric test so I need to be able to do this in seconds.
Original post by loloway
No it was not given. This question is from a Psychometric test so I need to be able to do this in seconds.


Your method was fine then. Perhaps you should make sure you know the first few multiples of the positive integers up to 20?

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you