Can anyone help me with this question??

Question

You are driving to your friends' house to pick them up to go to the movie theatre. The movie starts in 40 minutes. It takes you 10 mins to drive to your friends', and from there 15 more minutes to drive to the theatre at 40 miles per hour. You figured that you will reach ten minutes before the start of the movie. You expected your friends to be ready by the time you reach their place. Unfortunately, they were playing games, and it took 20 minutes for all of you to head out again from there. How fast should you drive now to reach the theatre before the movie begins? Provide your answer in miles per hours.

Answer 1

What a fun problem! Minus the extra information, your problem boils down to this:

You have 40 minutes total to reach the movie theater.

1. 10 minutes to your friend's house,
2. 20 minutes waiting,
3. which leaves 10 minutes to get to the theater on time.

The problem gives the time and speed to get to the theater (15 minutes @ 40 mile per hour).

Converting minutes to hours, use the distance-rate-time formula to calculate how far away the theater is.

d = r * t where t = minutes/60 hrs

This is the distance you must travel in 10 minutes remaining before the movie starts. So use the distance-rate-time formula again (with 10 minutes as time and the distance d you found) to find out how fast you will need to drive. Hope that helps!