This is a unit rate question

Question

A Horse named Northern dancer won the Kentucky derby with a time of exactly 2 minutes. At this rate, how long would it take Northern dancer to run the Belmont stakes? The Kentucky derby is running fo Horse named Northern dancer won the Kentucky derby with a time of exactly 2 minutes. At this rate, how long would it take Northern dancer to run the Belmont stakes? The Kentucky Derby is  1 1/4 miles in the Belmont stakes is 1 1/2 miles. 

Answer 1

set up a proportion using minutes/mile:

 

2/(1 1/4) = x/(1 1/2)

 

2/(5/4) = x/(3/2)

(5/4)x = (3/2)(2)

(5/4)x = 3

x = 3(4/5)

x = 12/5

x = 2 2/5 minutes