grade ten math - help quick!!

[jodiiss]

The cost of renting a car depends on teh number of days, for which it is renterd and the distance it is driven, The cost for one day and 240km is $39.00. The cost for three days and 800km is $125.00. What is the cost per day and the cost per km?

d+240k=39
3d+800k=125

[~max~]

Mmmh. Not an expert, my maths days are long gone but I thought it'd be:
$39 for one day and 240 KM. Multiply by number of days, and add $1 per 10Km after 240Km per day?

For 3 days at $39 and 240 Km, you'd pay $117.
But if you drove 800km, it means you drove 80km more than your "allowance". If you paid $125 for it, means you paid $8 for those 80km, which makes it 1$ per extra 10km.

Probably wrong though, as I'd expect they'll need a function of sorts...

[Bushwhacker]

$15 per day

10 cents per km

[~max~]

lol Bushwacker....I knew I was wrong, but now I'm curious. Can you explain please? Just personal enlightenment....:O)

[Tichfield]

D+240K=39
3d+800K=125

So D=(39-240K)

So 3d=(117-720K)

So 117-720K+8ooK=125

So 80K=8

So K=0.1

So D+24 =39

So D=15

[~max~]

Wow....Thanks Tichfield! Can't believe how much I forgot in all these years! :O(

[JUNKMAN]

$15 a day - 10c per km

240 x 10c = $24 + $15 = $39

800 x 10c = $80 + ($15 x 3 ) = $125

[JUNKMAN]

Sorry - spent so long checking my answers - didn't notice other replies!!

[figure]

Where were you Tichfield and JUNKMAN when I need help with my assignments? ;-)
Lucky you jodiiss! They explained in details too, you are so lucky. lol

[Tichfield]

I am not doing any more of his homework for him!

LOL

[jodiiss]

i am femaleee lol!

[Tichfield]

Sorry! I am not doing any more of her homework then.

LOL

[JUNKMAN]

Well I hope you pass whatever test or exam these questions were from!!

Could we have some history/geography questions next time ?? (:o)

[jodiiss]

thank you..

and im not the greateest in either of those subjects. my strengths are in art and gym. haha