The way we work this out is by working out the amount of lots of 25 seconds in an hour, and then multiply it by that 1/4 of an hour. 1 hour has 60 minutes, and each minute has 60 seconds, so 1 x 60 x 60 = 3600 = the number of seconds in an hour.
3600/25 = 144. Therefore there are 144 lots of 25 seconds in an hour. If the deer runs 1/4 a mile in 25 seconds, then we just have to do 144 x 1/4 and it will give us the answer.
144 x 1/4 = 36. Therefore the deer can run 36 miles per hour.
If you want to express this all in one equation, we can write it as:
((60 x 60)/25) x 1/4 = 36
Hope this helped :))
