22% since 100-78 is 22 so that is the percentage of numbers between 78 and 100
A
rational number is any number that can be written as the
ratio between two other numbers i.e. in the form

Part A:
An easy choice that makes sense is 7.8, right in the middle. To prove that it's rational we need to write it as a ratio. In this case we have

Part B:
We need a number that can't be written as a ratio (because it neither terminates nor repeats). Some common ones are

,

,

and

so it makes sense to try and use those to build our number. In this case

works nicely.
Answer:
Step-by-step explanation:
Let the first term is a and common difference is d.
<u>The nth term is:</u>
<u>We have:</u>
<u>The difference of these terms is:</u>
- (a + 8d) - (a + 5d) = 16 - 15
- 3d = 1
- d = 1/3
<u>Then the first term is:</u>
- a + 5*1/3 = 15
- a = 15 - 5/3 = 13 1/3
<u>The nth term equation is:</u>
- aₙ = 13 1/3 + 1/3(n - 1) = 1/3n + 13
<u>If the nth term is 22, find n:</u>
- 1/3n + 13 = 22
- 1/3n = 22 - 13
- 1/3n = 9
- n = 9*3
- n = 27
I think the 3rd one idk wait for someone else to answer go compare
There should be 3 more girls than boys in the class (9 boys, 12 girls)