Answer: Alex is 15 years
Step-by-step explanation:
Since Alex is w years old and her sister is three years younger than him. The age of his sister will be:
= w - 3.
We will then multiply their ages and equate to 180. This will be:
w × (w - 3) = 180
w² - 3w = 180
w² - 3w - 180 = 0
w² - 15w + 12w - 180 = 0
w(w - 15) + 12(w - 15) = 0
(w + 12)(w - 15)
w - 15 = 0
w = 0 + 15
w = 15 years
Alex is 15 years, her sister is 12 years.
Length of the side of the equilateral triangle is 4cm
Answer:
The standard deviation of the number of defective bulbs produced in an hour is 6.615
Step-by-step explanation:
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
The expected value of the binomial distribution is:
The standard deviation of the binomial distribution is:
In this problem, we have that:
What is the standard deviation of the number of defective bulbs produced in an hour
The standard deviation of the number of defective bulbs produced in an hour is 6.615
Answer:
21 and 15
Step-by-step explanation:
7+5=12
36/12=3
so you multiply each number by 3 and get a ration of
21:15