(3+3i) - (13+15i)
=3+3i-13-15i
=-10-12i
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:
20% mark up
Step-by-step explanation:
[(48-40)/40]×100%= 20%
We can solve for the arc length using the formula shown below:
Arc Lenght = 2pi*r(central angle/360)
We need to convert the central angle such as:
Central angle = 23pi rad * (180°/pi rad) = 23*180
Radius = 24cm
Solving for arc length:
Arc length = 2*3.14 *24*(23*180/360)
Arc length = 1733.28 cm