Hey there! :D
Let's keep the fraction 5/7 in mind. We should be able to reduce everything to 5/7.
15:21 (divide both by 3) you get 5:7. That is equivalent.
10 to 14. Divide both by 2. 5 to 7. That is equivalent.
The correct answer is 28/20. That is not equivalent.
I hope this helps!
~kaikers
There are 24 possible answers, 6 are correct answers and 18 are incorrect answers. By use of the hypergeometric distribution the probabilities of each possible number of randomly selected correct answers can be found, as follows:
P(0) = 0.1379, P(1) = 0.3819, P(2) = 0.341, P(3) = 0.1213, P(4) = 0.017, P(5) = 0.0008, P(6) = 0.000007.
The expected or mean number of correct answers is found from:
The answer is: 1.4998
Step-by-step explanation:
987 → 789
987 - 789 = 198
876 → 678
876 - 678 = 198
765 → 567
765 - 567 = 198
654 → 456
654 - 456 = 198
543 → 345
543 - 345 = 198
432 → 234
432 - 234 = 198
321 → 123
321 - 123 = 198
Generally it is always like that:
3 ≤ x ≤ 9
100x + 10(x-1) + (x - 2) → 100(x - 2) + 10(x - 1) + x
(100x + 10(x - 1) + (x - 2)) - (100(x-2) + 10(x-1) + x)
= 100x + 10(x - 1) + (x - 2) - 100(x - 2) - 10(x - 1) - x <em>cancel 10(x - 1)</em>
= 100x + x - 2 - 100x + 200 - x <em>cancel 100x and x</em>
= 100 - 2
= 198