|By 660M; i hate the hard qs! on Saturday, December 28, 2002 - 09:32 pm: Edit|
Ok, im prepping for the SAT on my own and the 10 REAL SATs dont give explanations on how they found answers. Im a sped, so can u guys help?
1) It took juanita a total of 10 hrs to hike from the base of the mountain to the top and back down again by the same path. If while hiking she averaged 2km/hr going up and 3 km/hr coming down, HOW MANY KM was it from the base of the mt. to the top?
2) One side of a triangle has a length 6 and a second side 7. Which of the following could be the AREA??
OK, so i know the first one deals with average speed/rate, but not much else.
For the second, i know its based on the triangle inequality theorem (3rd side must >diff. <sum of two sides) but what do i do with that? HELP! I know this is a zinch for you 800 Math ppl.
|By 800 in math on Saturday, December 28, 2002 - 09:37 pm: Edit|
1)Let x=the time needed to go up, then
so the distance from the base to the top is: 2*6=12(km)
2)if this is a right triangle and those two sides are perpendicular, then the area is 6*7/2=21.So *II* is the answer.
|By 660M on Saturday, December 28, 2002 - 09:39 pm: Edit|
THANKS!! i love smart people!
|By 660M on Saturday, December 28, 2002 - 09:40 pm: Edit|
Note: these are the ones from the FIRST practice tests..expect a LOT more in the coming days/wks
|By Adam on Saturday, December 28, 2002 - 09:41 pm: Edit|
First one: 24 km
It has to be the same distance up and down
D = ST 6 X 2 = 12 and 3 X 4 = 12. add them together, you get 24.
2nd one: It could be I and II. Just find the maximum area - which would use the two given sides as the non-hypotenuse of a right-triangle, and that is 21. Anything else smaller can be made with different angles.
|By person on Saturday, December 28, 2002 - 09:42 pm: Edit|
the answer to number 1 is 12 km.
x = length
x/2 + x/3 = 10 hours
(5/6)(x) = 10
x = 12 km
there is no way for me to explain number 2. You just have to visualize or draw a picture which is impossible for me to do.
|By me on Saturday, December 28, 2002 - 09:43 pm: Edit|
otw up: 12km @ 2km/hr = 6 hr
otw down: 12km @ 3km/hr = 4 hr
6 hr + 4 hr = 10 hr
2) A = bh/2
plugging in 6 as base we get
A = 3h
now plugging in 13, 21, and 24 you see that it is possible to attain a height of 13/3 and 7. 8 is not possible because the second side has a length of 7 and no matter which way you swing it it will never be 8 from the base. plugging in 7 as the base will also work for this, but is more tedious.
|By adam on Saturday, December 28, 2002 - 09:43 pm: Edit|
And Im an idiot.
READ THE QUESTIONS CAREFULLY.
|By 660M on Saturday, December 28, 2002 - 09:44 pm: Edit|
o wait, i just checked the book...#2 is actually 21 and 13.(I and II)..i dont think you can just assume its a right triangle..does anybody else have a clue about the 2nd one? (the first is right tho,thanks)
|By 800 in math on Saturday, December 28, 2002 - 09:45 pm: Edit|
adam: why do you add the distances? It's not asking for the total distance she traveled.
I agree with you on the 2nd one. So the following item should be added
IV. both I and II
and the answer is IV
|By 800 in math on Saturday, December 28, 2002 - 09:48 pm: Edit|
SAT I math problems can be pretty tricky sometimes :P
|By Pat57575 (Pat57575) on Saturday, December 28, 2002 - 09:58 pm: Edit|
yet you managed to get an 800... how many did you miss...0, 1, 2?
|By 800m on Saturday, December 28, 2002 - 10:04 pm: Edit|
I think I missed 1(probably that was the experimental part though), while I messed up 4 of them on my first attempt and only got a 760.
|By Pat57575 (Pat57575) on Saturday, December 28, 2002 - 10:09 pm: Edit|
4?! Once I missed 2 and got 740!
|By 800m on Saturday, December 28, 2002 - 10:13 pm: Edit|
you were unlucky then...
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