Answer:
x: work a woman can do in 1 day
y: work a girl can do in 1 day
Then
2x + 7y =1/4
4x + 4y =1/3
4x + 14y =2/4 (1)
4x + 4y =1/3 (2)
=> Let (1) - (2), 10y =2/4-1/3 <=>10y = 1/6 <=> y = 1/(6x10) = 1/60 (work)
=> From (2),4x = 1/3 - 4x1/60 => 4x = 16/60 => x = 4/60 (work)
=> 1 day, a woman and a girl can do: 1/60+4/60 = 5/60 =1/12 (work)
Then, the day required for a woman and a girl to complete work: 12 days
Using it's formula, it is found that the mean of the discrete random variable is given by:
B. 30.47.
<h3>What is the mean of a discrete distribution?</h3>
The expected value of a discrete distribution is given by the <u>sum of each outcome multiplied by it's respective probability</u>.
Hence, considering the table, the mean of the discrete distribution is:
E(X) = 23 x 0.16 + 25 x 0.09 + 26 x 0.18 + 31 x 0.12 + 34 x 0.24 + 38 x 0.21 = 30.47.
Hence option B is correct.
More can be learned about the mean of a discrete random variable at brainly.com/question/26660401
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Answer:

Step-by-step explanation:

Answer:
109
Step-by-step explanation:
15+15+15= 45
7+7+7=21
4+4+4=12
4+15×7=109
I hope this helps!
Answer:2284
Step-by-step explanation: