Answer: There are 
ways of doing this
Hi!
To solve this problem we can think in term of binary numbers. Let's start with an example:
n=5, A = {1, 2 ,3}, B = {4,5}
We can think of A as 11100, number 1 meaning "this element is in A" and number 0 meaning "this element is not in A"
And we can think of B as 00011.
Thinking like this, the empty set is 00000, and [n] =11111 (this is the case A=empty set, B=[n])
This representation is a 5 digit binary number. There are 
of these numbers. Each one of this is a possible selection of A and B. But there are repetitions: 11100 is the same selection as 00011. So we have to divide by two. The total number of ways of selecting A and B is the 
.
This can be easily generalized to n bits.
Answer: 90
Step-by-step explanation:
c = 2πr
r = 15
d = 30
30π = 90
Answer:
The third number is 180.
Step-by-step explanation:
Let the third number be 9x where x is an integer.
48 = 2*2*2*2*3
264 = 2*2*2*3*11
9x = 3*3*x
2*2*2*2*3*3*11*x = 7920y where y is an integer
1584x = 7920y
so x = 7920y / 1584= 5y.
Now the GCD is 12 so x must have 4 as one of its factors.
Also x is a multiple of 5 so it could be 20 then y would be 4.
If x = 20 then the third number is 9*20 = 180.
This checks out OK.
To the nearest whole number would be 57, because .6 rounds up to the next whole number
Answer:
25
Step-by-step explanation:
25x14=350
