rate of blowing balloons of Alexa = 15/20 = 0.75
rate of blowing balloons of Sara = 18/25 = 0.72
rate of blowing balloons of Shirley= 16/21 = 0.76
rate of blowing balloons of Sam = 12/23 = 0.52
from above calculation we concluded Shirley can blow balloons at the fastest rate!
1. Y = 10x
2. Y = 100 + 30x
3. Y = 50 + 1x
5. Y = 15 + .12x
The number of permutations of the 26 letters of the English alphabet that do not contain any of the strings fish, rat, or bird is 402619359782336797900800000
Let

Then

Note that since
, 
But since
, 
and
, 
Since

where 
and

What we are looking for is the number of permutations of the 26 letters of the alphabet that do not contain the strings fish, rat or bird, or

This link contains another solved problem on permutations:
brainly.com/question/7951365