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

Guest Mar 27, 2022

#1**0 **

Let the time it takes you to catch up to your friend==T

5T ==3 [T + 5], solve for T

5T ==3T + 15

5T - 3T ==15

2T == 15

**T ==15 / 2 ==7.5 minutes -for you to catch up to her**

**7.5 + 5 ==12.50 minutes - your friend had been walking when you caught up to her.**

Guest Mar 27, 2022

#2**+1 **

5 min = 1/12 hr in five minutes your friend will have a 3 m/hr * 1/12 hr = 1/4 mile head start

You are walking two miles per hour faster and will take 1/4 m / 2 m/hr = 1/8 hr to catch her = 7.5 mins

7.5 + 5 = 12.5 mins

ElectricPavlov Mar 28, 2022