A committee of 3 is being formed randomly from the employees at a school: 5 administrators, 34 teachers, and 4 staff. What is th
1 answer:
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Answer:
left
Step-by-step explanation:
The question says she used of it, so she probably used
of it. I'm assuming this is an error in the question, and it should be asking how much is left. To solve for that:
-
make denominators equal
( ×
) - (
×
)
-
Answer:
8%
Step-by-step explanation:
Hello,
<u>8% of the students take neither History or French</u>
so we have 8*200/100=8*2=16 students out of French and History
let s say that
a is the number of students taking only History
b is the number of students taking both History and French
c is the number of students taking only French
<u>10% of those who take History also take French</u>
so 0.10(a+b)=b <=> 0.10a+0.10b=b
<=> 0.10a+0.10b-0.10b=b-0.10b=0.9b
<=> 0.10a=0.90b
let's multiply by 10 it comes a = 9b
<u>4 times as many students take History as take French</u>
so a + b = 4 (b + c)
it comes 9b + b = 10b = 4b + 4c
<=> 10b-4b=4b+4c-4b=4c
<=> 6b=4c
<=> 3b=2c
<=> c = 3b/2
and we know that a + b + c = 200 - 16 = 184
so
9b + b + 3b/2 = 184 we can multiply by 2 it comes
20 b + 3b = 184*2
23b = 184*2 = 23 * 8 *2 = 23*16
b = 23*16/23 = 16
so b = 16
c = 3*16/2 = 24
c = 24
a = 9b = 144
a = 144
you can see the Venn diagram below
and then the probability that a student picked at random does History and French is 16/200 = 8%
so the answer is 8%
hope this helps
