Question

A series of ocean waves are moving past a surfer at a frequency of 25 waves per hour. approximately how many waves should the surfer expect during 45 minutes?

Answer 1

45 minutes corresponds to
`(3)/(4)` of hour. There are 25 waves per hour, so we must find how many waves there are in
`(3)/(4)` of hour. Therefore we can write the following proportion:

`25 waves: 1h = x : (3)/(4) h`
and by solving ,we find

`x= (25 \cdot (3)/(4) )/(1 )=18.75 waves`
So, the surfer should expect almost 19 waves in 45 minutes.