My friend sets out walking at a speed of $3$ miles per hour. I set out behind her $5$ minutes later at $4$ miles per hour. For how many minutes will my friend have been walking when I catch up to her?

Choff Jan 14, 2021

#1**+2 **

Best Answer

You need to cover the 1/4 mile head start.....you are walking 1 m/hr faster than your friend 1/4 m / 1 m/hr = 1/4 hr = 15 minutes to catch

Guest Jan 14, 2021

#2**+1 **

I got my answer form here: https://web2.0calc.com/questions/my-friend-any-help-is-appreciated

This answer is from CPhill:

At 3 mph....your friend covers 3 / 60 miles per minute

At 4 mph......you cover 4/ 60 miles per minute

So....every minute....you close [ 4 - 3 ]/ 60 = 1/ 60 miles on your friend

And when she has been walking for 5 minutes......she will be 5 * [3 / 60 ] = 15/60 = 1/4 of a mile ahead of you when you start

So......the number of minutes, m, it will take to catch your friend can be found by :

( 1/60) m = 1/4 multiply both sides by 60

m = 60 / 4 = 15 minutes

hihihi Jan 14, 2021

#4**+1 **

Figure out how far you walk in one minut at 3 miles per hour and figure out how far you walk in a minute at 4 miles per hour and add the 3 miles to itself and the 4 miles to itself and then add how far you go in 1 minute for the three or the four to the three or the four total and repeat until you either pass your friend or catch up to her and if you pass her figure out how far you are from her and subtract that from where you are

I am sorry if this is not helpful. I try my best =>

angelthecutehamster Jan 14, 2021