Melody

Maybe you just need to put the times sign in?

I found all these ones, that CPhill answered,  but the one you are asking now does not seem to be there.

Hi Sarah,

Do you have the address of your original question so that we can go to it?

(do you know what I mean? - just copy the address and paste it into a new post here)

It is good that you say when you do not understand but it is important that you say it on the original thread because the answerer want your feedback.  

People often give trivial anwers because they do not think anyone is really trying to learn from it.  We get so little feedback here.  Many askers only want to copy the answer and do not really want to learn.

Anyway, if you have that original question can you please copy the address and post it in here and then I will help you some more. :)

prime factor tree of 72

\(72=2^3*3^2\)

What is 7/8 high 3

\((\frac{7}{8})^3=\frac{7^3}{8^3}=\frac{343}{512}\)

Hello :)

You question is incomplete and as it stands it is total nonsense.

Are you refering to a triangle, a square or an elephant perhaps?

Is it a special triangle that you are talking about, I suspect it is, what is special about the triangle?? 

Sixty per cent of students applying for admissions at NGASCE are female. 30 applications were received on a particular day. What is the probability that exactly 15 of the applications will be from females?

\(\binom{30}{15} * 0.6^{15}*0.4^{15}\approx 0.078 \)

nCr(30,15)*0.6^15*0.4^15 = 0.078312209686080141065170452

What is the probability that fewer than 10 of the applications will be from females?

nCr(30,0)*0.6^0*0.4^30+nCr(30,1)*0.6^1*0.4^29+nCr(30,2)*0.6^2*0.4^28+nCr(30,3)*0.6^3*0.4^27+nCr(30,4)*0.6^4*0.4^26+nCr(30,5)*0.6^5*0.4^25+nCr(30,6)*0.6^6*0.4^24+nCr(30,7)*0.6^7*0.4^23+nCr(30,8)*0.6^8*0.4^22+nCr(30,9)*0.6^9*0.4^21 = 0.0008563919557253

\(\text{P(less than 10 females)} \approx 0.000856\)

Also, calculate the expected number and variance of the number of applications from females?

The expected value is np = 30*0.6 = 18 females

The variance = np(1-p) = 30*0.6*0.4 = 7.2

YES I agree, sometimes the presentation is more confusing than necessary and I do not like it when multiply signs are left out for no good reason.

But

when a number is jambed up against an open bracket there is always an invisiable multiply sign.

so

-7 + 9 = x + 5 (-3)

means

-7 + 9 = x + 5 *(-3)

2        =  x  - 15

17      =  x

x       =  17

(csc(x)-cot(x))*(sec(x)-23(x))

\((csc(x)-cot(x))*(sec(x)-23(x))\\ =\left[\frac{1}{sinx}-\frac{cosx}{sinx}\right]\;\left[ \frac{1}{cosx}-23x \right]\\ =\left[\frac{1-cosx}{sinx}\right]\;\left[ \frac{1}{cosx}-23x \right]\\ \)

It is not very simplified.  Is there more to this question?