Can you check my answers please? Thank you
Ben is greeting customers at a music store. Of the first 20 people he sees enter the store, 9 are wearing jackets and 11 are not. What is the experimental probability that the next person to enter the store will be wearing a jacket? Enter your answer as a simplified fraction.
The experimental probability that the next person to enter the store will be wearing a jacket is 9/40. Correct?
Matt's house number is a two-digit number. Neither of the digits is 0 and the house number is even. What is the probability that Matt's house number is 18?
1/36 probability.
Philip rolls a number cube 12 times. Which is the best prediction for the number of times that he will roll a number that is odd and less than 5?
4 times.
1st:
Where did you get the denominator of 40 from, isn't it 9/20 ??
2nd:
correct
3rd:
prob(odd and less than five)
= 2/6 = 1/3
so out of 12 tries,
(1/3)12 = 4
correct
Philip rolls a number cube 12 times. Which is the best prediction for the number of times that he will roll a number that is odd and less than 5?
Jason, Erik, and Jamie are friends in art class. The teacher randomly chooses 2 of the 21 students in the class to work together on a project. What is the probability that two of these three friends will be chosen?
To check your answers, let's go through each question one by one.
For the first question:
Ben sees a total of 20 people, with 9 wearing jackets and 11 not wearing jackets. To calculate the experimental probability that the next person to enter will be wearing a jacket, you would divide the number of favorable outcomes (people wearing jackets) by the total number of possible outcomes (total number of people seen).
In this case, there are 9 people wearing jackets out of the total 20 people seen. So the experimental probability is 9/20, not 9/40.
For the second question:
We are given that Matt's house number is a two-digit number that is even and neither of the digits is 0. We need to determine the probability of Matt's house number being 18.
Since we are looking for the number 18 specifically, and there are a total of 90 two-digit numbers (10 numbers from 10 to 19 and 9 numbers from 20 to 99 that have even digits other than 0), the probability of Matt's house number being 18 is 1/90, not 1/36.
For the third question:
Philip rolls a number cube 12 times. We need to make a prediction for the number of times he rolls an odd number less than 5.
Since there are 6 possible outcomes for rolling a number on a standard number cube (1, 2, 3, 4, 5, and 6) and half of them (1, 3) are odd numbers less than 5, the best prediction would be 12 times divided by 2, which is 6 times, not 4 times.
So, based on the corrections, the correct answers are:
1. The experimental probability that the next person to enter the store will be wearing a jacket is 9/20.
2. The probability of Matt's house number being 18 is 1/90.
3. The best prediction for the number of times Philip will roll an odd number less than 5 is 6 times.