The result of rolling a number cube 7 times is a 7-digit number composed of digits 1,2,3,4,5 and 6 so that digits can repeat. The total number of possibilities is 6^7.
The number of possibilities where 4 appears exactly two times is 5^5*(7!-6!/2).
5^5 is the number of 5-digits numbers composed of digits 1,2,3,5 and 6 so that digits can repeat.
7! is the number of permutations of digits 1,2,3,4,4,5 and 6.
6! is the number of permutations of digits 1,2,3,{4,4},5 and 6.
We don't want to subtract all numbers where digits 4 appear side by side. That's why we must divide 6! by 2.
Finally, the probability is P=5^5(7!-6!/2)/7^7
Answer:
9 books on each shelf
Step-by-step explanation:
43 + 29 = 72 books total
72/8 = 9 books per shelf
I believe it's 12 because 5*16=80. So, then you would subtract 4 from 16 and gat 12.
Answer:
100 N
Step-by-step explanation:
f= 0.05*2000=100 N
