00:01
A woman keeps fit by bicycling and running every day.
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On monday, she spends half an hour at each activity covering a total of 12 miles and 12 and half miles.
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On tuesday, she runs 12 minutes and cycles 45 minutes covering a total of 16 miles.
00:19
Assuming that her running and cycling speeds don't change from day to day, find these speeds.
00:25
Okay, so we have two variables.
00:27
The two types of activities, which is bicycling and running.
00:31
So let's let x well her running speed.
00:49
And let's let y equal to the speed of our bicycle.
01:01
So we know that her running and cycling speeds don't change from day to day.
01:08
They're always the same.
01:10
And on one day, she cycled or she ran.
01:16
She spent half an hour running and half an hour bicycling and that total up to 12 miles and 12 .5 miles.
01:35
Okay, so let's make 12 .5 5 into a whole fraction.
01:41
So 12 over 1 half is equal to 12 times 2, which is 24 plus 1.
01:46
So we have 25 over 2, a complex faction.
01:55
So 25 over 2.
01:59
And now we have on tuesday she runs 12 minutes per hour...