There are 7/4 gallons leaking per hour. This is the same as 1.75 gallons per hour. Hope this helps! :)
Answer:
0.173 probability that she gets exactly three questions correct.
Step-by-step explanation:
For each question, there are only two possible outcomes. Either she guesses the correct answer, or she does not. The probability of guessing the correct answer for a question is independent of other questions. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
Seven questions:
This means that 
Each question has four choices.
Abby guesses, which means that 
Find the probability to the nearest thousandth, that Abby gets exactly three questions correct.
This is P(X = 3).


Answer:
-71
Step-by-step explanation:
let 'n' = a number
2(143 + 2n) = 0n + 2
2(143 + 2n) = 2
143 + 2n = 1
2n = -142
n = -71