Answer:
Gregory will catch up Efren after 26 minutes 40 seconds.
Explanation:
Distance traveled = Speed x Time
Speed of Efren = 4 mi/h
Speed of Gregory = 8.5 mi/h
Let the time of catch up be t hours.
Time of journey of Efren before catch up = (t+0.5)hours, since he starts before half hour.
Distance traveled by Efren = 4 x (t+0.5) miles
Time of journey of Gregory before catch up = t hours.
Distance traveled by Gregory = 8.5 x t miles
If they catch up the distance traveled by them is same, so equating both distances.
4 x (t+0.5) = 8.5 x t
4.5t = 2
t = 0.44 hours =26.67 minutes = 26 minutes 40 seconds.
So Gregory will catch up Efren after 26 minutes 40 seconds.
Answer:
0.289792.
Step-by-step explanation:
If we define a month with one or more accident as "success"; and
A month with no accident as "failure" .
- P(one or more accidents will occur during any given month)=0.60.
- P(no accident will occur during any given month)=1-0.60=0.40
We want to calculate the probability that there will be at least four months in which no accidents occur before the fourth month in which at least one accident occurs.
in this case, let k=number of failures before the fourth success
Therefore, 
k follows a negative binomial distribution.
Therefore, the probability is:
![P(k\geq 4)=1-P(k\leq 3)\\=1-\sum_{k=0}^{3}\left(\begin{array}{ccc}3+k\\k\end{array}\right)(0.60)^4(0.40)^k\\=1-(0.60)^4 \left[\left(\begin{array}{ccc}3\\0\end{array}\right)(0.40)^0+\left(\begin{array}{ccc}4\\1\end{array}\right)(0.40)^1+\left(\begin{array}{ccc}5\\2\end{array}\right)(0.40)^2+\left(\begin{array}{ccc}6\\3\end{array}\right)(0.40)^3\right]\\=1-(0.60)^4 \left[ 1+1.6+1.6+1.28\right]\\=1-(0.60)^4[5.48]\\=0.289792](https://tex.z-dn.net/?f=P%28k%5Cgeq%204%29%3D1-P%28k%5Cleq%203%29%5C%5C%3D1-%5Csum_%7Bk%3D0%7D%5E%7B3%7D%5Cleft%28%5Cbegin%7Barray%7D%7Bccc%7D3%2Bk%5C%5Ck%5Cend%7Barray%7D%5Cright%29%280.60%29%5E4%280.40%29%5Ek%5C%5C%3D1-%280.60%29%5E4%20%5Cleft%5B%5Cleft%28%5Cbegin%7Barray%7D%7Bccc%7D3%5C%5C0%5Cend%7Barray%7D%5Cright%29%280.40%29%5E0%2B%5Cleft%28%5Cbegin%7Barray%7D%7Bccc%7D4%5C%5C1%5Cend%7Barray%7D%5Cright%29%280.40%29%5E1%2B%5Cleft%28%5Cbegin%7Barray%7D%7Bccc%7D5%5C%5C2%5Cend%7Barray%7D%5Cright%29%280.40%29%5E2%2B%5Cleft%28%5Cbegin%7Barray%7D%7Bccc%7D6%5C%5C3%5Cend%7Barray%7D%5Cright%29%280.40%29%5E3%5Cright%5D%5C%5C%3D1-%280.60%29%5E4%20%5Cleft%5B%201%2B1.6%2B1.6%2B1.28%5Cright%5D%5C%5C%3D1-%280.60%29%5E4%5B5.48%5D%5C%5C%3D0.289792)
The required probability is 0.289792.
We do the midpoint formula to find the center of the circle to get the left side of the equation.
Midpoint = [(X₁ + X₂) / 2 , (Y₁ + Y₂) / 2]
Now plug in:
[(8 + 4) / 2 , (- 6 - 2) / 2]
(12 / 2 , - 8 / 2)
(6, - 4)
The center of the circle is (6, -4)
Now we plug it into the equation of a circle:
(x - h)² + (y - k)² = r² where (h, k) is the center of the circle and r is the radius.
(x - 6)² + (y + 4)² = r² is the left side of the equation. This will eliminate options A and C
Now we do the distance formula using the center and an endpoint to get the radius. The formula for distance is:
√((X₂ - X₁)² + (Y₂ - Y₁)²)
We plug in using either of the endpoints.
√((4 - 6)² + (- 2 - (- 4))²)
√((-2)² + 2²)
√(4 + 4)
√8
√8 is your radius
(√8)² = 8
Your correct answer is (x - 6)² + (y + 4)² = 8, Option D
I checked all answers on Photomath.
Let me know if that’s helpful.
Answer:
88
Step-by-step explanation:
