Answer:
D
Step-by-step explanation:
(40-10)/7
The maximum amount of money she wants to spend is $40
Her adult ticket costs $10
She will pay for the children’s tickets with the remaining money
Each child’s ticket costs $7
To find the number of children she can take we need to use this expression (40-10)/7
Mrs Herñàndez can take 4 children
If you have multiple equations with multiple variables, you can either do clever substitutions, or turn it into a matrix on which you can perform linear combinations or multiplications (Gauss elimination)
1 1 1 1
2 1 -1 8
1 -1 1 -5
(note how the above 3 rows represent the 3 equations, just got rid of the variables, plus sign and equals sign)
subtract row1 from row3, that eliminates x and z from row 3.
1 1 1 1
2 1 -1 8
0 -2 0 -6
divide row3 by -2, that will give y a factor of 1
1 1 1 1
2 1 -1 8
0 1 0 3
The last row now says y=3
There are 2 answers: Choice 1, Choice 4
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Why is this? Because we use the rule
P(A & B) = P(A) * P(B)
which only works if events A and B are independent
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For the first answer choice,
P(A) * P(B) = 0.6*0.4 = 0.24 = P(A & B)
so that matches.
The same applies to the fourth answer choice as well
P(A) * P(B) = 0.3*0.2= 0.06 = P(A & B)
----
The other answer choices don't match up.
The second answer choice has
P(A) * P(B) = 0.3*0.4 = 0.12 but that doesn't match with the 0.70 given
Similarly for the third answer choice,
P(A) * P(B) = 0.5*0.1 = 0.05 which doesn't match with the 0.60
Answer:
70
Step-by-step explanation:
