Which ratio correctly compares 120 cm to 80 mm? A. 3 to 20 B. 3 to 2 C. 15 to 1 D. 150 to 1

An urn contains 5 red balls and 2 green balls. Two balls are drawn one after the other. What is the probability that the second

AleksAgata [21]

Answer:

The probability that the second ball is red is 71%

Step-by-step explanation:

Probabilities

We know there are 5 red balls and 2 green balls. Let's analyze what can happen when two balls are drawn in sequence (no reposition).

The first ball can be red (R) or green (G). The probability that it's red is computed by

$\displaystyle P(R)=\frac{5}{7}$

The probability is's green is computed by

$\displaystyle P(G)=\frac{2}{7}$

If we have drawn a red ball, there are only 4 of them out of 6 in the urn, so the probability to draw a second red ball is

$\displaystyle P(RR)=\frac{5}{7}\cdot \frac{4}{6}=\frac{10}{21}$

If we have drawn a green ball, there are still 5 red balls out of 6 in the urn, so the probability to draw a red ball now is

$\displaystyle P(GR)=\frac{2}{7}\cdot \frac{5}{6}=\frac{5}{21}$

The total probability of the second ball being red is

$\displaystyle P(XR)=\frac{10}{21}+\frac{5}{21}=\frac{5}{7}=0.71$

The probability that the second ball is red is 71%

7 0

3 years ago

BRAINLIEST AND 20 POINTS ANSWER ASAP PLZ

galben [10]

R = m - v + 2, where r = faces, v = vertices, and m = edges

r = 28 - 13 + 2
r = 15 + 2
r = 17, so the first answer is correct.

7. The surface area of a cone is A = pi*r*sqrt(r^2 + H^2)

A = pi*(7)(sqrt(49 + 1849)
A = pi*(7)(43.57)
A = pi*305 = 959 m^2, so the first answer is correct.

13. The volume of the slab is V = HLW
V = (5 yards)(5 yards)(1/12 yards)
V = 25/12 cubic yards

So it costs $46.00*(25/12) = $95.83 of total concrete. The third answer is correct.

21. First, find the volume of the rectangular prism. V = HLW
V = (15 cm)(5 cm)(7 cm)
V = 525 cm^3

Next, find the volume of the pyramid. V = 1/3(BH), where H is the height of the pyramid and B is the area of the base of the pyramid. Note that B = (15 cm)(5 cm) = 75 cm^2

V = (1/3)(75 cm^2)(13 cm)
V = 325 cm^3

Add the two volumes together, the total volume is 850 cm^3. The fourth answer is correct.

22. The volume of a square pyramid is V = 1/3(S^2)(H), where S is the side length and H is the height.

V = (1/3)(20^2 in^2)(21 in)
V = 2800 in^3

Now that we know the volume of this pyramid, and that both pyramids have equal volume, we plugin our V to the equation for the volume.

2800 = (1/3)(84)(S^2)
2800 = 28S^2
100 = S^2
 10 in = S, so we have a side length of 10 in, and the first answer is correct.

3 0

3 years ago

3.64 + 3/5 tell me the answer plz

kifflom [539]

Answer:

$\huge\boxed{4.24}$