Answer:
10.5774194, you can round up as many ways as you want.
5x + 4x = 720
9x = 720 (divide by 9)
X= 80
In order to get the bigger ratio, which is 5, you would substitute x for 80. (I'm bad at explaining)
Work:
5(80)= 400
The answer would be 24 because 24-4 is 20
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
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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:
