30 girls , 12 were selected
40 boys, 16 were selected
We can simplify these down by finding the Greatest Common Factor in both girls and boys:
30:12 .... 15:6 .... 1 : 2.5 30/12 .... 15/6 .... 2.5
40:16 .... 20:8 .... 1 : 2.5 OR 40/16 .... 20/8 .... 2.5
They are equal ratios because their most simplified ratios/fractions are equivalent
Just take n=1,2,3,4,5 respectively to find out the first 5 terms.
First 5 terms = 4,3,2.25,1.69 respectively.
For the 5th partial sum, just add the first 5 terms.
5th partial sum = 10.34
....
First 4 terms : 5,8,11,14 respectively.
Now you need to find the other next 4 terms to find out the 8th partial sum.
17,20,23,26
8th partial sum = 124
Hope this helps:)
<h3>
Answer: Choice C</h3>
P = 11/40 + 1/4 - 1/20
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Explanation:
The formula we use is
P(A or B) = P(A) + P(B) - P(A and B)
In this case,
- P(A) = 22/80 = 11/40 = probability of picking someone from consumer education
- P(B) = 20/80 = 1/4 = probability of picking someone taking French
- P(A and B) = 4/80 = 1/20 = probability of picking someone taking both classes
So,
P(A or B) = P(A) + P(B) - P(A and B)
P(A or B) = 11/40 + 1/4 - 1/20
which is why choice C is the answer
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Note: P(A and B) = 1/20 which is nonzero, so events A and B are not mutually exclusive.
