4 Quesions in Quantitative review I need help with

Question

Hello
I was wondering if anyone can explain to me how they got the answers to the following problems. I cant figure out how they got these answers. Good news I got everything else on the problem solving part of the quant down

Thank you in advance

Thank you in advance

nitostyle · Answer

in addition

sludge · Answer

Maybe the first one is deceiving me but...

elapsed time =  *hours 
so if 22 = 6*2s, 2s = 22/6

so 12  = 44, E.

ywilfred · Answer

Let the time for each stroke = x = time inteverval between strokes

x+x+x+x+x+x+x+x+x+x+x = 22 seconds
11x = 22
x = 2

There will be 23x for 12 strokes, so 23*2 = 46 seconds.

ywilfred · Answer

2nd qn:

The number of table entries = 6C2 = 15 (because we want to see the number of ways to pair up 2 cities for table entries).

Alternatively, you could very quickly write out the combinations, AB,AC,AD,AE,AF,BC,BD,BE, BF.... etc, and then count them.

3rd qn:
x-y=o is not one of the bounding lines. x-y can be written as x = y and this is a positive rising slope cutting through the origin.

sludge · Answer

Good catch. There wouldn't be a time delay after the last ring :oops:

ywilfred · Answer

3rd qn:

nc2 + n >= 12
we need n to be 5.

nitostyle · Answer

Thanks for the response, but how did you know you needed to use that formula?

saikadelik · Answer

last question:

lets say you choose x colors

no of ways you can arrange x colors in groups of AT MOST 2 is
 = x + x arranged in groups of 2
= xC1 + xC2

xC1 + xC2 >=12

From here on i pluged in numbers for x and got 5. hope this helps.

gk2k2 · Answer

Ok. Here is my way of solving these problems.
Q1. Ans: D
It takes as much time to strike as to wait. Therefore between 2 strikes there is 1 interval (t) or n-1 interval for n strikes.
At 6 hours it took 22 sec => (n+n-1)t = 22 => 11t = 22 => t = 2sec.
Therefore at 12 hours, time taken 
= (12*2-1)2 
= 46 sec

Q2. Ans: C
To find distance between any 2 cities you need only 1 entry.
So you would require only 5 entries. Correct me if I am wrong

Q3. Ans: D
A) Y-axis
B) X-axis
C)There is a line at X=1 (vertical line || to y-axis)
D) This is the answer
E)Points (0,1) and (2,0) satisfy this equation

Q4. Ans: C
If you use 1 color no. of colors required would be 12
Obviously you need no. of colors less than that.
Try answers that are less than 12 and make sure that one of the choices is greater or equal to nC2
Why?? You should be able to select 2 colors from a given number of colors.
4C2 = 6 -- not enough combinations for 12 boxes
5C2 = 10 -- not enough
6C2 = 15 -- this is correct answer

nitostyle · Answer

Thank you all for your response. I see where you get the answers now

4 Quesions in Quantitative review I need help with

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