Complete Question
The complete question is shown on the first uploaded image
Answer:
The correct option is B
Explanation:
The number of alphabet is n= 4 (a , b , c , d )
Generally the total number of string of length 10 over the 4 alphabets is

Gnerally the number of string of length 10 that does not include b is
Generally the number of strings of length 10 over the 4 alphabets that have at least one alphabet b somewhere in the string is

=> 
Maybe show a picture ? I don’t get the question .
A synonym for the slope of a line is the <em>rate of change</em>. However, one purpose for the slope of the line is the determine whether the linear relationship has a positive correlation or a negative correlation. Based off of this, your answer most likely is D.
Answer:
The coefficient of friction should in the majority of cases, remain constant no matter what your normal force is. When you apply a greater normal force, the frictional force increases, and your coefficient of friction stays the same. Here's another way to think about it: because the force of friction is equal to the normal force times the coefficient of friction, we expect (in theory) an increase in friction when the normal force is increased.
One more thing, the coefficient of friction is a property of the materials being "rubbed", and this property usually does not depend on the normal force