9√5+√5
=22.360679775
&
6√2+5√2-15√2
=-5.656854249
Answer:
8.6
Step-by-step explanation:
a^2+b^2=c^2
7^2+5^2=c^2
49+25=c^2
74=c^2
8.6=c
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
Its D 15+15+15= 45 so there for it will be 45
