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#1 2005-10-18 17:39:24

Nikky
Guest

HELP! Math Question

Can someone help with this?

...

A person drives at a constant speed of 97km/h except for a break that he takes which is 26.4 minutes long. If the average speed of the trip is 64km/h...

How long did the whole trip take?
How far does the person go?

#2 2005-10-18 18:09:15

ryos
Member
Registered: 2005-08-04
Posts: 394

Re: HELP! Math Question

speed = distance / time
Average speed also = distance / time

Assume two chunks of time: t1 spent driving at 97 km/hr and t2=26.4min spend driving at 0 km/hr

Convert break to hours: 26.4/60 = 0.44 hr
Average the speeds:  (s1 + s2) / (t1 + 0.44)

(97 + 0) / (t1 + 0.44) = 64
t1 = 97/64 - 0.44 = 1.075625

Or, total time = 1.515625 hr and total distance = 64 km/hr * 1.075625 hr = 68.84 km.

But, I may have done it wrong. It's late and I haven't checked for mistakes...

Last edited by ryos (2005-10-18 18:15:43)


El que pega primero pega dos veces.

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#3 2005-10-18 20:09:36

ganesh
Moderator
Registered: 2005-06-28
Posts: 13,490

Re: HELP! Math Question

Checked, found right.


Character is who you are when no one is looking.

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#4 2005-10-19 23:00:04

DAN
Guest

Re: HELP! Math Question

I love maths. It's so fun and exciting. Please tell me more. Oh maths!! (Jelly babies)

#5 2005-10-19 23:35:25

justlookingforthemoment
Moderator
Registered: 2005-05-26
Posts: 2,161

Re: HELP! Math Question

Insomnia...? You have a jelly baby fan friend.

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#6 2005-10-20 00:43:10

MathsIsFun
Administrator
Registered: 2005-01-21
Posts: 7,535

Re: HELP! Math Question

You can combine maths and jelly babies. Count them.


"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

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#7 2005-10-20 03:15:31

insomnia
Real Member
Registered: 2005-03-23
Posts: 944

Re: HELP! Math Question

Actually I edited his post as he was being abusive. *I hate maths* was what he said. So I changed it.


Friends are angels who lift our feet when our own wings have trouble remembering how to fly

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#8 2005-10-20 09:16:46

MathsIsFun
Administrator
Registered: 2005-01-21
Posts: 7,535

Re: HELP! Math Question

Oh, and they would probably be the first to notice if they didn't get the right change.


"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

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