Question

A bourse named northern dancer won the Kentucky derby by running 1 1/4 miles in exactly 2 minutes. At this constant rate, how long does it take northern dancer to run the 1 1/2 mile Belmont stakes? Use unit rate

Answer 1

It is given that there are

`1(1)/(4)=(5)/(4)\text{miles}`

run in 2 minutes.

So, we have to determine time required to run

`1(1)/(2)=(3)/(2)\text{miles}`

Apply the unitary method,

For 5/4 miles required 2 minutes.

So , for 1 miles, time required

`(2)/((5)/(4))=(2*4)/(5)=(8)/(5)\min`

Therefore,for 3/2 miles , time required is

`(3)/(2)*(8)/(5)=(12)/(5)\text{min}=2.4\min`

Hence the time required is 2.4 minutes.