This expression cannot be simplified any further.
Explique melhor, se eu entender consigo te ajuda :)
Answer:
There are 21 ways to choose the first person, 20 ways to choose the second, 19 ways for the third and 18 ways for the fourth so the answer is 21 * 20 * 19 * 18 = 143640.
I need the answer too. My brother needs it.
False, every time in the sequence, the numbers are doubling, therefore, the next number in the sequence would be 16.
