Answer: its 4 lol just look at the other side and you see the 4 there lol
Step-by-step explanation:
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:
3/8
Step-by-step explanation:
So what I did is make 1/2 have a common denominator with 1/8. The common denominator would be 4/8. Then i added 1/8 and 4/8 and got 5/8. Then I subtracted 5/8 and 8/8 because 8/8 would be the 100% chance. Then I got 3/8. So I would then think the chance of getting a yellow marble would be 3/8 chance. I hope I helped :)
Answer:
All three.
Step-by-step explanation:
All three of these ratios are equivalent to 15:5. Here's how:
Let's look at the first ratio, 9:3. Did you notice something common? 3 x 3 = 9. 9/3 = 3. 5 x 3 = 15. 15/3 = 5. Both of these numbers are divisible by 3, so these ratios are equivalent.
Second. 6:2. 2 x 3 = 6. 6/3 = 2. 5 x 3 = 15. 15/3 = 5. See the similarity? The same applies to the next problem, number three, although it does slightly differentiate.
Third, 3:1. See, here, since the ratio is smaller than the problem, we can't multiply, since this ratio is smaller than the original number. But, it's still the same thing. A ratio is a number that compares a value to another value. This means that 3:1 is 3 compared to one. Now, let me clarify. 15:5. 3:1. These are the exact same values, except they are just written in a different form, and simplified. Since 5 x 3 = 15, we know that we can divide 15 evenly by 5, which makes it 3, and divide 5 evenly by 5, which equals one. So here we have our answer for the third problem. 5:1.
Ratios are basically division, except simplified. Every single ratio problem works this way. Once you get the hang of it, it's immensely easy. Hope this helped!
Answer:
The least number of stamps required is 
Step-by-step explanation:
Let the number of 
cent stamps be 
and 
cent stamps be 
We have
The minimum number is obtained when more cent stamps are used
Here cannot be greater than 
since 
Substitute 
Not possible since is not a fraction
Substitute 
Not possible since is not a fraction
Substitute 
Possible
Hence minimum number of stamps is
