5<x≤100
x∈(5;100] x has to be greater but not equal to 5 and less and equal to 100
Answer:
Final amount = initial balance ( 1 + ( intrest rate * time ) )
This is a problem dealing with permutations and combinations.
Order does not matter in this problem.
Since order doesn't matter, it is a combination.
Repetition matters, since you can't have the same person count as two people.
There are twelve slots.
_ _ _ _ _ _ _ _ _ _ _ _
Each slot needs to be multiplied by the next.
_*_*_*_*_*_*_*_*_*_*_*_
Now we have to fill in the slots.
Each slot will be filled with a number one less than the one before it. It has to be one less, since repetition matters.
The numbers will be decreasing from 30, since there are 30 possible people.
30 * 29 * 28 * 27 * 26 * 25 * 24 * 23 * 22 * 21 * 20 * 19
Multiply these numbers together and you get your answer.
41,430,393,164,160,000 ways
Combine the like terms by adding the coefficients,
->5x^4 can't add anything so leave it there,
->-3x^3 can add -3x^3 which gives you -6x^3,
->We can't do anything with -11x^2 so leave it there as well,
->6x add to -(-8x) gives you 14x,
You will get for your final answer is 5x^4-6x^3-11x^2+14x.
Distance = r x t ===> t=d/r
Distance (after 2 hours driving @30mil/hr) = 2 x 30 = 60 Mil
To drive same distance (60) with r = 50, the time needed is 60/50 =1.2 hrs