Given that 8% of the students are Swedish, this means that 100 - 8 = 92% are not Swedish.
Let S represent the event that a student is Swedish and N represent the event that a student is not a Swedish.
Then, the probability that a student chosen at random is a Swedish, P(S), = 8% = 0.08
The probability that a student chosen at random is not a Swedish, P(N), = 92% = 0.92
That the first Swedish person found was on the third trial means that the first and second trial produced a non-Swedish.
Therefore, the required probability = 0.92 x 0.92 x 0.08 = 0.068 to three decimal places.
A(1) = - 3 ;
a(2) = a(1) + ( 2 - 1 )d ;
3 = -3 + d ;
d = 6 ;
a(3) = a(1) + ( 3 - 1)d;
9 = - 3 + 2d ;
12 = 2d ;
d = 6 ;
a(4) = a(1) + ( 4 - 1 )d ;
15 = -3 + 3d ;
18 = 3d ;
d = 6 ;
Then, a(n) = - 3 + ( n- 1 )6 ;
a(n) = - 3 + 6n - 6 ;
a(n) = 6n - 9 is an explicit functin rule for the sequence -3, 3, 9, 15, ...
Let's say "p" people were going to the expedition initially, and the cost for each was "c", now, we know the total cost is 1800, so for "p", folks that'd be 1800/p how much each one cost, namely, how many times "p" goes into 1800.
well, prior to leaving, 15 dropped out, so that leaves us with " p - 15 ", and the cost "c" bumped up to " c + 27 " for each.

![\bf 1800p=1800(p-15)+27[p(p-15)] \\\\\\ 1800p=1800p-27000+27(p^2-15p) \\\\\\ 0=-27000+27(p^2-15p)\implies 0=-27000+27p^2-405p \\\\\\ \textit{now, let's take a common factor of }27 \\\\\\ 0=p^2-15p-1000\implies 0=(p-40)(p+25)\implies p= \begin{cases} \boxed{40}\\ -25 \end{cases}](https://tex.z-dn.net/?f=%5Cbf%201800p%3D1800%28p-15%29%2B27%5Bp%28p-15%29%5D%0A%5C%5C%5C%5C%5C%5C%0A1800p%3D1800p-27000%2B27%28p%5E2-15p%29%0A%5C%5C%5C%5C%5C%5C%0A0%3D-27000%2B27%28p%5E2-15p%29%5Cimplies%200%3D-27000%2B27p%5E2-405p%0A%5C%5C%5C%5C%5C%5C%0A%5Ctextit%7Bnow%2C%20let%27s%20take%20a%20common%20factor%20of%20%7D27%0A%5C%5C%5C%5C%5C%5C%0A0%3Dp%5E2-15p-1000%5Cimplies%200%3D%28p-40%29%28p%2B25%29%5Cimplies%20p%3D%0A%5Cbegin%7Bcases%7D%0A%5Cboxed%7B40%7D%5C%5C%0A-25%0A%5Cend%7Bcases%7D)
well, you can't have a negative value of people... so it has to be 40.
so, 40 folks were initially going, then 15 dropped out, how many went on the expedition? 40 - 15.
Ok so
8000=cost
profit-8000
then
another cost is 15rand per mug
but profit of 35 rand
35-15=20
profit of 20rand per mug
profit=R20m-8000
where m=number of mugs sold
(R20 means 20 rand)
f(m)=R20m-8000