math help !!!!!!

ahmed97 · August 19, 2013, 3:36am

photon354 · August 19, 2013, 4:01am

Answer is E. As you had $30 base charge and u paid $105 in total, u paid $75(105-30) for each 1mph extra speed. As u pay $5 for each extra 1mph increase in speed, u had (75/15) mph extra speed.i.e. 15 extra mph from the base mph I.e. 20 … Now your speed will be base+extra speed = 20+15=35 … Hope that helps!

ahmed97 · August 19, 2013, 4:22am

ahmed97 · August 19, 2013, 4:45am

muhammad9211 · August 19, 2013, 5:31am

Q15.

The answer is E.
First u wanna convert 64 to base 2. 64=2^6. Now u can cancel the bases since both sides have base 2. Now u have mt=6. All the choices have m as the subject so make m the subject. Divide by t and u get m=6/t. Which corresponds to E

muhammad9211 · August 19, 2013, 5:34am

Second Q15.

Best u can do is substitute a value. Assume 1/k as 0.135 (it fits the criteria)
K is about 7.41.
Using calc. (K-1)/K = 0.865
The tenths digit is 8
So the answer is D.
You can check with any number. You will always get 8 as ur tenths digit

darksaber21 · August 19, 2013, 11:15am

With the second Q15, it’s easier if you can recognize that the fraction (k-1)/k is the same as 1 - 1/k, where 1/k is slightly greater than 0.13 as given (so 1/k must be between 0.13 and 0.14). If you realize that, then you can just perform basic subtration:

1 - 0.13 ≈ 0.87

So, the result is between 0.86 and 0.87. Regardless of the result, the tenths place has an 8, which makes the answer D. Thus, this problem is possible to do without a calculator.

Sikorsky · August 19, 2013, 11:29am

Muhammad’s answer is correct. I think darksaber’s is correct and mathematically superior. For good or ill, the SAT doesn’t test for “mathematically superior,” only for correct!

muhammad9211 · August 19, 2013, 1:35pm

@sikorsky, i think that in the method by darksaber, although correct, may be difficult for people with lower level math. I dont know the score range ahmed is scoring in, so i gave a fool proof way to do this. There is a greater risk in error by using darksabers way. Although if ur math base is strong, u might find it easier to utilize that method

photon354 · August 19, 2013, 1:43pm

A x B x+y C (x+y)/2 D E
|_|||||||||||—>

Q. In the number-line above, which of the letters represents y? (Each mark is evenly spaced)
Options: A,B,C,D,E

photon354 · August 19, 2013, 1:46pm

Ignore the previous one, this looks better:

A x B x+y C (x+y)/2 D E
|_|||||||||||—>

Q. In the number-line above, which of the letters represents y? (Each mark is evenly spaced)
Options: A,B,C,D,E

photon354 · August 19, 2013, 1:57pm

I am sorry for the above two posts but CC doesn’t let me to mark the letters as I want to. Anyways I’ll give the directions for marking each letter. Starting from the very left, the first mark is labelled A then the mark two units to its left is labelled x, then one unit left from x is B, then x+y, then C, then (x+y)/2 each 1 unit left to its preceding term. Then two units left from (x+y)/2 mark D and again two units left from it mark E. I want to apologize again for the inconvenience. Finally, can anyone tell me how I can upload a pic of a question.

ahmed97 · August 20, 2013, 2:34am

the answer is E because as c is the middle of the line and the value of c is the average of x+y / 2 so y will be in the other end for example |2_|2+4/2|4__|

ahmed97 · August 20, 2013, 2:37am

@muhammad9211 my score range in math is from about 700 to 730 i usually make 3 wrong and 1 left in a math test so how can i improve my score range ??? thnx u for ur help

photon354 · August 20, 2013, 3:57am

@ahmed97 I could not quite understand ur explanation. Would you please clarify it once again?
I had also came up with the same answer earlier(I supposed D=0, (x+y)/2 = -2 and (x+y)=4 ) but this calculation takes a long time. Here’s the question once again:

<a href=“http://i41.■■■■■■■.com/142rp01.jpg[/IMG]”>http://i41.■■■■■■■.com/142rp01.jpg

</a>

photon354 · August 20, 2013, 3:59am

Another one :

<a href=“http://i44.■■■■■■■.com/juvi9u.jpg[/IMG]”>http://i44.■■■■■■■.com/juvi9u.jpg

</a>

muhammad9211 · August 20, 2013, 4:14am

For the first one.

Take the equation (x+y)/2=x+4.

I formed that equation because the lines are evenly spaced. And the value of (x+y)/2 is seen to be four spaces greater than x.

(x+y)/2=x+4

x+y=2x+8

y=x+8

Y is 8 spaces greater than x. Count 8 spaces from x and u will be on E.

There is probably a better method but this is the first to come to mind and it worked

ahmed97 · August 20, 2013, 4:22am

for the second one Step 1: 39
Step 2: 41 -->39+2
Step 3: 20.5 -->41/2
Answer: 20

muhammad9211 · August 20, 2013, 4:32am

Yea dude. The second one should be really easy probably a 1 or 2. Theyve given u the number and a set of operations u need to perform.

ahmed97 · August 20, 2013, 4:35am

. how many positive integers less than 100 are multiples of 5 and are equal to 3 times an even integer?

i solved in this way 
X even * 3 = a multiple of six 
so 5 * 6 =30
1000 /30 =33 1/3

so the answer = 33

/is it’s right to solve it in this way ??

math help !!!!!!

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