Question

Kathy & Leslie drove total of 225 miles in 5.2 hours. Kathy drove first part of the trip & averaged 45 miles per hour. Leslie drove remainder & averaged 55 miles per hour. For what length of time did Kathy drive?

Answer 1

first part as in like first half?

Answer 2

Yes.

Answer 3

If x = time Kathy drove and y=time Leslie drove
x+y=5.2 hours
and
45x + 55y = 225 miles

Answer 4

Let us assume Kathy Drove for x hours
so Leslie drove for (5.2-x) hours

45x + 55(5.2-x) = 225
solve for x

Answer 5

@sheg 45+286-55x=225?

Answer 6

@pfenn1 Thank you for your help too.

Answer 7

you are welcome.

Answer 8

So, I'm kind of stuck on what @sheg said. Is it 45+286-55x=225?

Answer 9

yes, now solve for x

Answer 10

I got like 1.9.

Answer 11

The answer is 3.1 hours but I don't understand how to get that.

Answer 12

wait i feel we are going in the wrong direction

Answer 13

Ah, me too.

Answer 14

Im sorry this troubling.

Answer 15

The problem is when you expanded the equation
45x + 55(5.2-x) = 225
should be 45x+286-55x=225
I didn't notice that the x had been dropped from the first term. Try it again now that the equation has been corrected.

Answer 16

Your right! Okay, let me try this again.

Answer 17

@sheg, you developed it correctly, we just didn't notice the dropped x.

Answer 18

So I did the problem and I got the answer 6.1.

Answer 19

check it again.....you should have gotten 3.1....

Answer 20

Ugh okay lol.

Answer 21

cause its 45x-55x=-10x+286 then subtract equals -61 so then -10x=-61 then divide i got 6.1?

Answer 22

your question i feel is not correct how can they drive @ a speed of 45 and 55 but still take 5.2hours i m getting 4.3 hours

Answer 23

I could upload the picture.

Answer 24

Did you copy the total distance correctly in the original problem. I'm guessing it was 255 miles total, not 225 miles. It is getting really late and I think we are all getting tired and making mistakes. I was using 255 even though it said 225 so I got the right answer when I did it.

Answer 25

hey average speed of kathy and leslie is (45+55)/2 = 50miles/hr
and they can cover 225miles in 225/50 = 9/2 = 4.5 hours

Answer 26

Im so dumb it was 255 :(

Answer 27

Im really sorry guys. :( I got it from here now. Thank you.

Answer 28

my god @amandamv1994 you r great

Answer 29

No, you are not dumb. It was just a typo that we all missed.

Answer 30

Haha i can't believe I read it wrong! Grrrr.

Answer 31

But your help still helped me so thank you!

Answer 32

I can't believe I read it wrong and got the wrong answer using the the wrong "tight" number LOL!

Answer 33

I meant got the *right answer and I meant "right" not "tight"
I'm going to bed. I am too old to be so late.

Answer 34

I meant up so late

Answer 35

Sorry to both of you :(

Answer 36

no problem. sorry it took so long for us to find the mistakes.....you were doing it right all along but just with typos. good night.

Answer 37

Goodnight!