Answer:
There are 220 ways by which the medals can be awarded to three of the 15 gymnast, if exactly one of the Americans wins a medal
Step-by-step explanation:
From the question, we have;
The number of gymnast in the Olympic women's competition = 15
The number of the gymnast who are Americans = 4
The number of medals awarded = 3 medals
The number of ways hat the medals can be awarded to the three of the gymnast if exactly one of the Americans wins a medal is given as follows;
The number of ways one of the medals can be won by one of the four Americans = ₄C₁ = 4 ways
The number of ways the other two medals can be won by the remaining 11 gymnast = ₁₁C₂ = 55 ways
Therefore, the total number of ways, 'N', the medals can be awarded to three of the 15 gymnast, if exactly one of the Americans wins a medal is given as follows;
N = ₄C₁ × ₁₁C₂
∴ N = 4 × 55 = 220
Answer:
see explanation
Step-by-step explanation:
given 
To rationalise multiply the numerator/denominator by the conjugate of the denominator
the conjugate of 3 + 7i is 3 - 7i, hence

distribute the numerator/denominator
=
[ note that i² = - 1 ]
= 
= 
=
+
i
=
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i ← in standard form
<u>(a) Construct a 95% confidence interval for the difference between the average number of intrusion attempts per day before and after the change of firewall setting (assume equal variance)</u>
Answer:
3
Step-by-step explanation:
Given that:
Integers : x, x + 1, x + 2
6x - 2(x + 1) = (x+2) + 5
6x - 2x - 2 = x + 2 + 5
4x - 2 = x + 7
4x - x = 7 + 2
3x = 9
x = 9/3
x = 3
First integer = x = 3
2nd integer = x + 1 = 3+1 = 4
3rd Integer = x + 1 + 1 = 3 + 2 = 5