Basim

If n is an integer and (n)^3 is divisible by 24 then what is the largest number that must be a factor of n?

a) 1

b) 2

c) 6

d) 8

e) 12

The answer apparently is 6 but I think it should be 12 considering 12 is also factor of it self. Thoughts?

Thanks.

I'm studying the anatomy of the stomach and I have found conflicting descriptions of the pyloric portion of the stomach.

For example, Lipincott here labels the region between the pyloric sphincter as the pyloric canal. Also, quoting from book: "Pyloric canal: constricted passage through pyloric sphincter made of circular muscle fibers". Interestingly, it makes no mention of the pyloric orifice.

I've seen most books make a distinction between the two (KLM, Gray's). They say the pyloric canal is the narrow region ending at the pyloric sphincter and the region the sphincter encloses is the pyloric orifice. (or that is, at least, what I've managed to understand from them)

So which one is it? Thanks.

I'm a bit embarrassed to ask this question because I should know this at my level but I'm confused.

Can anyone help me round the following numbers to 3 decimal places?

0.010016 (my guess: 0.010)

0.0000156 (my guess: 0.000 but it looks weird adding so many zeroes that don't really mean anything lol)

Thanks.

How do we solve:

[4^(x+1)] = [5^(2x-3)]

I got till:

(x+1)/(2x-3) = (log[5])/(log[4])

but now I'm stuck.

Help? :) Thanks.

Flask X contains 5 dm3 of helium at 12 kPa pressure and flask Y contains 10 dm3 of neon at 6 kPa

pressure. If the flasks are connected at constant temperature, what is the final pressure?

A 8kPa B 9kPa C 10kPa D 11kPa

I have no idea how to do this. I feel so helpless. Help? :-|

(PS: I know the answer. I just don't know how to get to it.)

Thanks.

1) Find out how many even numbers between 3000 and 7000 can be written down using the digits 1, 3, 6 and 8 if repetition of digits is allowed.

The answer for is 64. How do we do this?

2) A team of 6 people is to be chosen from a list of 10 candidates. Find out in how many ways can this be done if the team consists of a 1st pair, a 2nd pair and a 3rd pair but the order within each pair does not matter. Ans: 18900. How?

3) 4 men, 2 women and a child sit at a round table. Find the number of ways of arranging the 7 people if the child is seated between 2 men. Ans: 288. How?

4) The seats at a round table are numbered from 1 to 7. Find the number of ways in which a committee consisting of 4 men and 3 women can be seated at the table if all the men sit together. Ans: 1008. How?

5) In how many ways can 5 different books be distributed among 10 people if each person can get any number of books. Ans: 10^5. How?

You don't have to answer all. Even if you know one, just answer.

Thanks. :-)

The equation of a curve is xy = 12 and the equation of a line 'l' is 2x + y = k, where k is a constant.

In the case where k = 10, one of the points of intersection in P (2,6). Find the angle, in degrees correct to 1 decimal place, between 'l' and the tangent to the curve at P.

My attempt:

I got the tangent's equation. It's y = -3x + 12.

I don't know how to get the angle. We've learned the formula cos θ = (a.b)/(|a|*|b|). If we can find the answer using this, and you can show me how it would be great!

Thanks!

During terminal velocity the upward force (air resistance) is equal to the downward force (weight). Why, then, does the object continue to have motion downwards (and not stay still in air)?

Likewise, a car travelling at constant velocity has equal forward and backward forces. Why does it still move then?

I read the answer to this in a book a long time ago but I can't seem to find that book now. :(

Thanks for any help.

1) A boy has 3 bags P, Q, R, each of which contains 20 balls. P contains 5 black balls, Q contains 10 black balls and R contains 15 black balls. The rest of the balls are white. If he draws a black ball from P he next draws from Q, otherwise he draws from R. If he draws a black ball from Q he next draws from R, otherwise he draws from P. If he draws a black ball from R he next draws from P, otherwise he draws from Q. Whenever a ball is drawn it is always replaced before another ball is drawn. If he always starts with bag P, find the probability that, after five draws, he has not drawn from bag R.

My attempt:

According to me, the question is asking for P{P, Q, P, Q, P}. This = (5/20)^3 X (10/20)^2 = 1/256.

The answer however is 1/64.

2) A die with faces numbered 1 to 6 is biased so that P{score is r} = kr, ( r = 1, ... ,6). Find the value of k.

If the die is thrown twice calculate the probability that the total score exceeds 10.

My attempt:

I can't figure out how to find k. The answer says k = 1/21 and I know the 21 comes from adding 1k + 2k ... 6k. But that's all.

Thanks in advance everyone. :-)

What would be the single best link you would give me if I asked you to explain Einstein's Theory of Relativity, to me?

I don't just mean his formula. I want all his ideas about time and space, well-explained. Please don't just google it and give me a random link. I need something that's worth spending time on (something you've read/written yourself perhaps?)

Thanks. :-)

Hello everybody!,

I was wondering if anyone can hack into papers of CIE, for IGCSE and GCE of 2009, Oct/Nov. Please, somebody, help me!!!

Answer me so that I can tell you which papers I want, specifically.

Thanks in advance