Answer: 0.9961
Step-by-step explanation:
Given: Total choices to each question = 4
So, the probability that an answer is correct = 
Total questions = 20
i.e. n= 20
Let x be the binomial variable that represents the number of correct answers.
So, the probability that the student has at least 10 correct answers.

[By using cumulative binomial table]
Hence, the probability that the student has at least 10 correct answers = 0.9961
Answer:
It's a
Step-by-step explanation:
This is a quadratic expression with the highest power of X being 2.
The coefficient of X² = 1
Note that the general form of a quadratic equation is aX² + bX + C
In this question,
a = 1
b = 7
C = 10
First step is to multiply a and C ( a x C)
= 1 X 10 = 10
Then, find 2 factors of 10 which can both add up to give 7, the coefficient of X given in the question.
The possible factors of 10 are 5 and 2. The sum of 5 and 2 is
5 + 2
Hence, the equation can be written as;
X² + 7X + 10 = X² + 5X + 2X + 10
The next step is to group using a bracket and factorise each bracket individually
(X² + 5X) + (2X + 10) =
X( X + 5) + 2( X + 5) =
(X + 5) (X + 2)
(X + 5) (X + 2) are the factors of the quadratic equation, X² + 7X + 10
Answer:
$1.53
Step-by-step explanation:
Sales Tax Rate = 8.25%
Book Sales Cost = $18.50
Book Sales Tax = 8.25% x $18.50
= 8.25/100 x $18.50
= 0.0825 x $18.50
Book Sales Tax = $1.53
It would weight 18lbs i believe