A multiple-choice test contains 25 questions, each with 4 answers. Assume a student just guesses on each question. (a) What is the probability that the student answers more than 20 questions correctly

9.68*10^-10

Step-by-step explanation:

The problem above can be solved using the binomial probability relation :

Where ;

P(x = x) = nCx * p^x * q^(n-x)

n = number of trials = 25

p = 1/4 = 0.25

q = 1 - p = 0.75

x = 20

P(x > 20) = p(x = 21) + p(x = 22) +.. + p(x = 25)

Using the binomial probability calculator to save computation time :

P(x > 20) = 9.68*10^-10

no, the equation would be invalid since they are both not equal.

step-by-step explanation:

here you got

4y-6+4y 2-9

first, you would simplify the equation on the form.

4y-6+4y 2-9

then, move all the terms that contains a y to the left and all the other terms to the right.

+4y-4y+-9-6

finally, you will simplify the left and the right side of the equation.

y=-3

total amount of money that he should pay if he has not used his duty free exemption is $98

step-by-step explanation:

given a united states citizen returning to the states declares the following items at the customs office: 3 shirts at $8.50 each 2 dresses at $27.50 each 1 pair of gold cuff links at $17.50 per pair. we have to find how much he pay

cost of 3 shirts if one cost at $8.50 is

cost of 2 dresses if one cost at $27.50 is  

cost of 1 pair of gold cuff at $17.50

so, total amount of money that he should pay if he has not used his duty free exemption is   $25.5+$55+$17.50=$98