the dimensions shown are an approximation using these dimensions which is the approximate area of abc

Which expressions are equivalent to -6n + (-12) + 4n?

creativ13 [48]

The answer is A. 4(n 3) - 6n

6 0

3 years ago

Damon makes 20 cups of lemonade by mixing lemon juice and water. The ratio of lemon juice to water is shown in the tape diagram.

Effectus [21]

Answer: 4 cup

Step-by-step explanation:

Here, the total number of cups in lemonade = 20 cups

In which some are cup of lemon juice and some are cups of water.

And, the ratio of cups of lemon juice and water in one lemonade = 1 : 4

Let the cups of lemon juice in one lemonade = 1 x

And, The cups of water in one lemonade = 4 x

Where x is any number.

Thus, 1 x + 4 x = 20

⇒ 5 x = 20

⇒ x = 20/5 = 4

Thus, Damon uses 4 cup of lemon juice in one lemonade.

6 0

3 years ago

Read 2 more answers

Show that if X is a geometric random variable with parameter p, then

Lubov Fominskaja [6]

Answer:

$\sum_{k=1}^{\infty} \frac{p(1-p)^{k-1}}{k}=-\frac{p ln p}{1-p}$

Step-by-step explanation:

The geometric distribution represents "the number of failures before you get a success in a series of Bernoulli trials. This discrete probability distribution is represented by the probability density function:"

$P(X=x)=(1-p)^{x-1} p$

Let X the random variable that measures the number os trials until the first success, we know that X follows this distribution:

$X\sim Geo (1-p)$

In order to find the expected value E(1/X) we need to find this sum:

$E(X)=\sum_{k=1}^{\infty} \frac{p(1-p)^{k-1}}{k}$

Lets consider the following series:

$\sum_{k=1}^{\infty} b^{k-1}$

And let's assume that this series is a power series with b a number between (0,1). If we apply integration of this series we have this:

$\int_{0}^b \sum_{k=1}^{\infty} r^{k-1}=\sum_{k=1}^{\infty} \int_{0}^b r^{k-1} dt=\sum_{k=1}^{\infty} \frac{b^k}{k}$ (a)

On the last step we assume that $0\leq r\leq b$ and $\sum_{k=1}^{\infty} r^{k-1}=\frac{1}{1-r}$ , then the integral on the left part of equation (a) would be 1. And we have: