The probability that you guess correctly on any given question is 20% (since there are five choices on each question). What is the probability that you are able to guess ten or more correct answers?

The probability that you are able to guess ten or more correct answers is P(x≥10) = 0.0026

Step-by-step explanation:

The question is incomplete:

You take a multiple choice test that you are not prepared for, so you have to guess on all twenty questions. The probability that you guess correctly on any given question is 20% (since there are five choices on each question). What is the probability that you are able to guess ten or more correct answers?

This can be modeled by a binomial random variable, with sample size n=20 and probabillity of success p=0.2.

The probability of guessing k answers right can be calculated as:

We have to calculate the probabiltiy that 10 or more answers are correctly answered guessing: P(x≥10)

341

step-by-step explanation:

all you have to do is 9x31 (which equals 279) and then 20x31 (which equals 620). then you have to subtract. 620-279=341.