The answer is 135 and 45.
Hope this helps?
Answer:
a) 0.0016
b) 0.0224
Step-by-step explanation:
If every question has 5 possible answers, the probability of getting the correct answer by guessing would be 0.20. The probability of getting an incorrect answer would be 0.80.
a)Find the probability she lucks out and answers all four questions correctly.
To do this, Allison would have to guess right the first, second, third AND fourth answers. Therefore, we have to multiply the probabilities:
0.20 x 0.20 x 0.20 x 0.20 = 0.0016
The probability that she answers all 4 questions correctly is 0.0016.
b) Find the probability that she passes the quiz.
To pass the quiz, she has to have three OR 4 correct answers:
- The probability that she has 3 correct answers is: 0.20 x 0.20 x 0.20 x 0.80 (since she has to have 1 correct answer and 1 incorrect one) = .0064.
- We already calculated the probability that she guesses 4 answers correctly: 0.0016.
Now, we have to sum up these two scenarios:
0.0064 + 0.016 = 0.0224.
Thus, the probability that she passes the quiz is 0.0224
Answer:
p = 250 - 15(w)
Step-by-step explanation:
Original amount: 250
No of weeks to return money: w
Amount to pay each week: 15
Amount that he has paid back: 15 × w (When we subtract this term from the total we will get the answer)
So after w weeks he owes his parents :
p = 250 - 15(w)