A Sound wave needs a medium for propogation. Hence, Sound cannot travel through a vacuum.

A vacuum is an area without any air, like space. So sound cannot travel through space because there is no matter for the vibrations to work in.

The given number series is 6, 6, 9, 18, 45, ?

Here the series follows a pattern that,

6 

6 x 1 = 6

6 x 1.5 = 9

9 x 2 = 18

18 x 2.5 = 45

45 x 3 = 135

Hence, the next number in the given number series is 135.

Appellate jurisdiction refers to the power of a higher court to review decisions and change outcomes of decisions of lower courts.

Pluto dwells on the inner edge of the The Kuiper belt which is a belt of asteroids that lies on the outer edge of the solar system.

Pluto is a dwarf planet that is supposed to be no longer a planet and is still considered a planet because of its history in the solar system.

It takes 248 years to make one orbit around the sun. As to where it is, depends on time.

Most of the emissions of greenhouse gases (GHG) come primarily from burning fossil fuels (coal, hydrocarbon gas liquids, natural gas, and petroleum) for energy use and the major greenhouse gas is of course carbon dioxide (CO2) which comes from burning fossil fuels and land-use change.

But methane (CH4) and nitrous oxide (N2O), which mostly come from agriculture and waste, are also significant GHGs and shouldn't be discounted.

Axis powers, the coalition headed by Germany, Italy, and Japan that opposed the Allied powers in World War II.

The "Axis powers" formally took the name after the Tripartite Pact was signed by Germany, Italy, and Japan on 27 September 1940, in Berlin.

The pact was subsequently joined by Hungary (20 November 1940), Romania (23 November 1940), Slovakia (24 November 1940), and Bulgaria (1 March 1941) and these were the nations that fought in World War II against the Allied forces.

Spyware is software that aims to gather information about a person or organization without their knowledge, that may send such information to another entity without the consumer's consent, or that asserts control over a device without the consumer's knowledge

Spyware is mostly used for the purposes of tracking and storing Internet users' movements on the Web and serving up pop-up ads to Internet users. Whenever spyware is used for malicious purposes, its presence is typically hidden from the user and can be difficult to detect. Some spyware, such as keyloggers, may be installed by the owner of a shared, corporate, or public computer intentionally in order to monitor users.

We know that, Total probability = 1

Given probability of black stones = 1/4

=> Probability of blue and white stones = 1 - 1/4 = 3/4

But, given blue + white stones =  9 + 6 = 15

Hence,

3/4 ----- 15

 1   -----  ?

=> 15 x 4/3 = 20.

Hence, total number of stones in the box = 20.