Ask question

Ask question

All categories

3 years ago

14

A metal alloy weighing 10 kg and containing 13% copper is melted and mixed with 4 kg of a different alloy which contains 83% cop

per. What percent of the resulting alloy is copper?

1 answer:

Vinil7 [7]3 years ago

4 0

Answer:

33%

Step-by-step explanation:

(13*10)+(83*4)=(14*x)

130+332=14x

462=14x

x=33

Please mark as Brainliest! :)

Have a nice day.

You might be interested in

Bethany is 62 in tall Bethany's brother scott is 3 inches taller than her she is write Scott's height in feet and inches

MrRissso [65]

Scott is 62+3=65 inches tall, and there are 12 inches in a foot, so you get 65/12=about 5 whole feet. 5 whole feet is 60 inches in total, so we have a leftover 5 inches, meaning that Scott is 5 feet and 5 inches tall.

8 0

3 years ago

what is the solution to the equation fraction 1 over 6x = 2? x = fraction 1 over 12 x = fraction 1 over 3 x = 3 x = 12

hram777 [196]

1/6x = 2.....multiply both sides by the reciprocal 6/1
(6/1)(1/6)x = 2(6/1)
1x or just x = 12

6 0

4 years ago

Read 2 more answers

(05.08A)Triangle ABC is transformed to similar triangle A′B′C′ below:

Romashka-Z-Leto [24]

Answer:

1st option is correct i.e., 1 over 2

Step-by-step explanation:

Given that Triangle ABC transformed to Triangle A'B'C'.

Coordinated of Triangle ABC are A(2,6) , B(2,4) and C(4,4)

Coordinated of Triangle A'B'C' are A'(1,3), B'(1,2) and C'(2,2)

Scale factor of Dilation is the no. of times coordinates of vertices of a figure increase or decrease.i.e.,

if A(a,b) ⇒ A'(c,d)

where, a.k=c & b.k=d then k is scale factor of dilation.

Value of k is same for all vertices.

For coordinates of A & A' ,we have $2.k=1\implies k=\frac{1}{2} \:\: and \:\: 6.k=3\implies k=\frac{1}{2}$

For coordinates of B & B' ,we have $2.k=1\implies k=\frac{1}{2} \:\: and \:\: 4.k=2\implies k=\frac{1}{2}$

For coordinates of C & C' ,we have $4.k=2\implies k=\frac{1}{2} \:\: and \:\: 4.k=2\implies k=\frac{1}{2}$

Therefore, the scale factor of dilation is $\:\frac{1}{2}\:$ since in all cases $k=\frac{1}{2}$

1st option is correct i.e., 1 over 2

3 0

3 years ago

How is 3/5 and 8/10 Are equivalent fractions?

olya-2409 [2.1K]

Hi!

These are not <span>equivalent fractions because 8/10 reduces to 4/5, not 3/5, therefore, they are not </span>equivalent.

4 0

3 years ago

A grower believes that one in five of his citrus trees are infected with the citrus red mite. How large a sample should be taken

mihalych1998 [28]

Answer:

n=6147

Step-by-step explanation:

1) Notation and definitions

$X=1$ number of citrus trees that are infected with the citrus red mite.

$n=5$ random sample taken

$\hat p=\frac{1}{5}=0.2$ estimated proportion of citrus trees that are infected with the citrus red mite.

$p$ true population proportion of citrus trees that are infected with the citrus red mite.

Me=0.01 represent the margin of error desired

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{\hat p(1-\hat p)}{n}})$

In order to find the critical values we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 95% of confidence, our significance level would be given by $\alpha=1-0.95=0.05$ and $\alpha/2 =0.025$ . And the critical values would be given by:

$t_{\alpha/2}=-1.96, t_{1-\alpha/2}=1.96$

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

And on this case we have that $ME =\pm 0.01$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

And replacing into equation (b) the values from part a we got:

$n=\frac{0.2(1-0.2)}{(\frac{0.01}{1.96})^2}=6146.56$

And rounded up we have that n=6147

5 0

3 years ago