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What does a 2:1 ratio mean?

2 Answers
Aug 23, 2016

A ratio is a comparison between two (or more) different quantities of the same unit.

A ratio does not tell us how many there are altogether, only how their numbers compare.

For example if the numbers of boys and girls at a hockey match are in the ratio #2:1# , we know the following information:

  • There are more boys than girls.

  • There are 2 boys for every girl

  • The number of boys is double the number of girls, which is the same as saying there are half as many girls as boys.

  • We do not know the total number of people at the match, but we do know that it is a multiple of 3.

  • #2/3# of the group are boys and #1/3# are girls.

If we are told that there are 720 people at the match, we will know that there are 480 boys and 240 girls.

#2/3 xx 720 = 480 " boys" and 1/3 xx 720 = 240 " girls"#

May 11, 2017


The number is split into two parts such that one is twice as large as the other.


For example, if you split 12 as a 2:1 ratio, you get 8 and 4 (one part twice is large as the other).

In general terms, you can work out the values like this:

#Ratio: a:b#
#Number =x#
#=(x/[a+b]).a : (x/[a+b]).b#