00:01
So in this problem, we have two friends that are 60 miles apart.
00:11
One person's over here.
00:13
One person's over here.
00:14
They decide to ride towards each other.
00:16
So sally starts from the college and heads east.
00:21
Okay, so remember if we had our little north, west, east, south, right? we know that in this case, sally is over here going in this direction.
00:33
And we know that teresa is starting in this side and going in this direction.
00:47
So here is a diagram that shows the distance that the two cycles are going to be riding towards each other.
00:58
So this is the answer to part a.
01:00
Second thing is, how far does each cyclist ride in t hours? now, in this case, right, we want to make sure that we're only working from one side of, of the picture or the other.
01:15
So we need to be able to kind of talk about this in a common sense, right? so in this case right here, we're basically saying like this is almost like zero and this is like 60, right? so what we're saying is how far does a cyclist ride in t hours, right? so we know that sally is riding at a rate of 21 miles per hour.
01:38
So 21 x, i'm sorry, 21, t is sally's rate, how far she travels in t hours.
01:49
We also know that teresa is riding at 15 miles per hour.
01:54
So 15 t...