Three fifths of the members of a hiking club went on the last hiking trip. It 39 people went on the trip, how many are in the club?

1 Answer

45

Explanation:

We can set up this kind of problem a few ways. Here's one:

We're told that the 39 people who went on a trip is the same as #3/5# of the total group.

We can express the ratio of the people who went on the trip against the total membership this way:

#"went on trip"/"total membership"#

And that ratio is equal to #3/5#:

#"went on trip"/"total membership"=3/5#

We know 39 people went on the trip:

#39/"total membership"=3/5#

If we multiply the right side by #13/13# (which we can do because anything divided by itself is 1):

#39/"total membership"=3/5(13/13)=39/45#

Therefore, the total membership is 45