If a student randomly guesses at 20 multiple-choice questions, find the probability that the student gets exactly four correct. each question has four possible choices.

Probability = 0.190

Step-by-step explanation:

Given:

Number of questions, 'n' = 20

Each question has four choices.

Let event of choosing correct answer be success and its probability be represented by 'p'.

Therefore, event of choosing wrong answer is failure and its probability be represented by 'q'.

Now, probability of success is choosing one correct answer out of 4 options. So,

Now, 'p' and 'q' are complements of each other. Therefore,

Now, we need 4 successes. Therefore,

Using Bernoulli's theorem to find 'x' successes from 'n' questions, we get:

Plug in 4 for 'x', 20 for 'n', 0.25 for 'p' and 0.75 for 'q'. Solve.

Therefore, the probability of getting 4 correct answers out of 20 questions is 0.190.

the answer is 62

answer

a,b, and d

explanation

a reflection angle is more than

but less than;

an angle that measures

is a reflex angle.(true)

an angle that measures less than

is acute.(true)

provided we are considering angles greater or equal to zero.

an acute angle lies in the range.

an obtuse angle is less than 180° but more than 90°

an angle that measures 300° is obtuse (false)

an angle that measures 65° is an acute angle.(true)