Answer:
you want 4 correct and 16 incorrect
there are 20 questions
each question has four answers, so
P(right answer) = 1/4
P(wrong answer) = 3/4
----
Since you want 4 correct of 20 we have a combination of 20C4
This is a binomial problem where p = 1/4, q = 3/4 and we get
(20 "choose" 4)*(probability correct)^(number correct)*(probability incorrect)^(number incorrect)
putting numbers in we get
(20c4)*(1/4)^4*(3/4)^16
This gives us
~ .189685
Step-by-step explanation:
The answer is 525 because it is the closest to the proportional ratio
Rewrite 13/40 as a fraction over 100:
13/40 = (2 • 6.5)/(2 • 20) = 6.5/20
6.5/20 = (6.5 • 5)/(20 • 5) = 32.5/100
32.5/100 = 0.325
which clearly terminates.
Answer:
I think 42 is the answer...
