9514 1404 393
Answer:
mutually exclusive
Step-by-step explanation:
The formula of interest is ...
P(A or B) = P(A) + P(B) - P(A and B)
Filling in the given values, we have ...
9/10 = 2/5 + 1/2 - P(A and B)
Solving for P(A and B), we get ...
P(A and B) = 2/5 +1/2 -9/10 = 4/10 +5/10 -9/10
P(A and B) = 0
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Events are mutually exclusive when <em>they can never happen at the same time</em>. That is, P(A and B) = 0.
The events A and B are mutually exclusive.
Answer: the answer is B
Step-by-step explanation:
Answer:
a=5, s=3
Step-by-step explanation:
a=adult s=student
then write 2 equations to represent the amount of people and money
a+s=8
7.25a+5.5s=52.75
• To solve a pair of equations using substitution, first solve one of the equations for one of the variables. Then substitute the result for that variable in the other equation.
{a+s=8, 7.25a+5.5s=52.75}
• Choose one of the equations and solve it for a by isolating a on the left hand side of the equal sign.
a+s=8
• Subtract s from both sides of the equation.
a=−s+8
• Substitute −s+8 for a in the other equation, 7.25a+5.5s=52.75.
7.25(−s+8)+5.5s=52.75
• Multiply 7.25 times −s+8.
−7.25s+58+5.5s=52.75
• Add −29s/4 to 11s/2.
−1.75s+58=52.75
• Subtract 58 from both sides of the equation.
−1.75s=−5.25
• Divide both sides of the equation by −1.75, which is the same as multiplying both sides by the reciprocal of the fraction.
s=3
• Substitute 3 for s in a=−s+8. Because the resulting equation contains only one variable, you can solve for a directly.
a=−3+8
• Add 8 to −3.
a=5