Tüm alıştırma soruları

A laboratory mixture is prepared by combining three liquid solutions: Solution X, Solution Y, and Solution Z. Initially, Solution X makes up $20\%$ of the total volume of the mixture. Solution Y's volume is $\frac{1}{3}$ of the combined volume of Solution X and Solution Z, and Solution Z makes up the remaining portion of the mixture. If $3.0$ liters of Solution Z are added to the mixture, Solution Z then constitutes exactly $58\%$ of the new total volume. What was the original total volume, in liters, of the mixture before Solution Z was added?

### Models of Yellowstone Volcanism

Yellowstone National Park is characterized by intense geothermal activity and a history of supervolcanic eruptions. The Yellowstone volcanic system has produced a southwest-to-northeast track of progressively younger volcanic calderas over the past $16.5$ million years. Geologists debate the primary mechanism driving this volcanism.

Model 1 (Plume Hypothesis)
Yellowstone volcanism is driven by a deep mantle plume—a narrow column of hot, buoyant rock rising from the core-mantle boundary (approximately $2{}900\text{ km}$ deep). This plume remains relatively stationary relative to the deep mantle. As the North American plate moves southwestward over this stationary plume at a rate of $2.3\text{ cm/year}$, decompression melting at the plume head generates magma that periodically erupts, leaving a path of calderas. The primary source of heat is primordial thermal energy from the Earth's core.

Model 2 (Lithospheric Extension Hypothesis)
Yellowstone volcanism is driven by shallow, upper-mantle processes and plate tectonics, not a deep plume. As the North American plate stretches and undergoes lithospheric extension due to tectonic forces, pre-existing crustal fault zones and shear lines fracture. This fracturing allows pre-existing, ambient magma in the upper mantle (at depths less than $200\text{ km}$) to escape to the surface. The age progression of the calderas is due to the sequential reactivations of these fault systems as stress propagates through the plate, rather than a stationary heat source. The primary source of heat is local radioactive decay and shear heating within the upper mantle.

Match each scientific claim or description below to the model(s) that support or include it.

### The Younger Dryas Cooling

The Younger Dryas was a period of abrupt cooling that occurred approximately $12,900$ years ago, temporarily reversing the warming trend after the last glacial maximum. Scientists debate the primary trigger of this event.

Hypothesis 1
Around $12,900$ years ago, a large cometary body fragmented and collided with Earth's atmosphere. This extraterrestrial impact caused widespread wildfires, rapid thermal shocks, and the sudden melting of large portions of the Laurentide Ice Sheet. The massive influx of freshwater into the North Atlantic Ocean reduced the salinity of the surface water. This dilution prevented the sinking of cold, dense water, shutting down the Atlantic Meridional Overturning Circulation (AMOC) and triggering global cooling.

Hypothesis 2
The cooling was initiated solely by terrestrial hydrological shifts, without any extraterrestrial influence. As the Laurentide Ice Sheet naturally retreated due to gradual solar warming, a massive ice dam holding back Lake Agassiz collapsed. This burst released an immense volume of freshwater directly into the Arctic Ocean and North Atlantic Ocean. The sudden decrease in ocean salinity disrupted the thermohaline circulation (AMOC), causing the rapid onset of the Younger Dryas cooling.

Hypothesis 3
The primary trigger was a period of intense volcanic activity. Multiple large-scale volcanic eruptions injected high volumes of sulfur dioxide ($\text{SO}_2$) gas into the stratosphere. These gases reacted with water vapor to form highly reflective sulfate aerosols, which blocked incoming solar radiation and cooled the Northern Hemisphere. This atmospheric cooling led to increased sea ice extent, which secondarily altered ocean circulation currents like the AMOC, sustaining the cold period.

According to Hypothesis 2, the freshwater influx that disrupted the AMOC was directly caused by which of the following events?

Read the passage below about marine conservation. Choose the word that most precisely and clearly fits the blank to maintain the formal, academic register of the passage.

While restoring the ancient Roman fresco, the delicate colors of the mural were carefully preserved by the conservator using organic solvents.

Which choice most clearly and logically corrects the underlined portion of the sentence?

A landscaping company uses a grass seed mixture containing perennial ryegrass and Kentucky bluegrass in a ratio of $5:3$ by weight. If a bag of this mixture contains $15$ pounds of Kentucky bluegrass, how many pounds of perennial ryegrass does it contain?

The museum curator wanted to display the rare, delicate artifacts that were recovered from the shipwreck, she carefully arranged them in a temperature-controlled case.

Which choice best punctuates the underlined portion of the sentence?

Because geodesic domes are constructed from a network of triangles, they distribute stress evenly throughout the structure, which is why they can support heavy loads and weights.

Which choice is the most effective and concise revision of the underlined portion of the sentence?

The following passage is about the nineteenth-century paleontologist Mary Anning. Read the passage and write the correct form of the verb 'unearth' in the blank to maintain a consistent verb tense throughout the text.

Before the spacecraft launched into orbit, engineers conducted several safety tests on the primary booster rockets.

Which choice is the best version of the underlined portion of the sentence?

A positive integer $n$ is a multiple of $7$, and the greatest common factor of $n$ and $120$ is $15$. Which of the following is a possible value for $n$?

A positive integer $K$ is a multiple of $10$ and has exactly $8$ positive factors (including $1$ and $K$). What is the least possible value of $K$?

Arrange the following numbers in order from least to greatest: $\frac{2}{5}$, $0.38$, $45\%$, and $0.42$.

When oceanographers first discovered hydrothermal vents in 1977, they were astounded by the thriving ecosystems surrounding these volcanic fissures. Located miles below the ocean surface, where sunlight cannot penetrate, these vents host unique organisms that rely on chemosynthesis rather than photosynthesis. To study these deep-sea communities, researchers must deploy sophisticated submersibles capable of withstanding the immense pressure of the abyss. This advanced equipment allows scientists to gather heaps of data about how life persists in such extreme environments.

Which choice best maintains the established style and tone of the passage?

Many urban planners are championing vertical farming as a sustainable method to produce fresh vegetables in crowded cities. Because these farms stack crops in vertical layers inside controlled environments, they save vast amounts of water and land. Furthermore, they eliminate the need for long-distance shipping, they can operate year-round regardless of weather conditions. This localized production significantly reduces carbon emissions associated with transporting food.

Which of the following options is the most grammatically correct replacement for the underlined portion?

A scientist monitors the temperature in three different chambers, $A$, $B$, and $C$. The temperature in Chamber $B$ is $T^\circ\text{C}$. The temperature in Chamber $A$ is always $5^\circ\text{C}$ colder than the temperature in Chamber $B$, and the temperature in Chamber $C$ is always $9^\circ\text{C}$ warmer than the temperature in Chamber $B$. If $T$ must be an integer, and the sum of the absolute values of the temperatures in all three chambers is minimized, what is the value of $T$?

A water purification plant processes raw water through three successive filtration stages: Stage A, Stage B, and Stage C. Stage A removes $\frac{3}{8}$ of the impurities present in the raw water. Stage B removes $40\%$ of the remaining impurities. Stage C removes $0.75$ of the impurities that remain after Stage B. If $4.5$ kilograms of impurities are successfully removed in Stage C, how many kilograms of impurities were originally in the raw water?

The passage below describes a famous historical site. The second sentence of the passage has been split into four segments.

'Overlooking the Urubamba River Valley, the ruins of a fifteenth-century Inca citadel continue to fascinate historians. [Segment 1] [Segment 2] [Segment 3] [Segment 4]'

Arrange the four segments below in the correct order to form a grammatically correct second sentence that avoids misplaced or dangling modifiers.

### Models of Martian Atmospheric Loss

Scientists agree that Mars once possessed a much thicker, warmer carbon dioxide ($CO_2$) atmosphere than it does today. However, they disagree on the primary mechanism responsible for the loss of this atmosphere.

Model 1
Mars lost its atmosphere primarily through *solar wind stripping*. Early in its history, Mars had a liquid core that generated a strong global magnetic field, protecting the atmosphere. Approximately 4 billion years ago, the core cooled, and the magnetic field decayed. Without magnetic protection, high-energy particles from the solar wind directly struck the upper atmosphere. These particles transferred energy to gaseous molecules (primarily $CO_2$ and $H_2O$), accelerating them past Mars's escape velocity. This continuous stripping depleted the atmosphere over hundreds of millions of years.

Model 2
Mars lost its atmosphere primarily through *impact erosion* during the Late Heavy Bombardment, a period of intense asteroid and comet impacts between 4.1 and 3.8 billion years ago. When large impactors struck Mars, they produced massive vapor plumes that expanded faster than Mars's escape velocity, driving large portions of the overlying atmosphere into space. Because Mars has a relatively low gravitational acceleration ($3.71\text{ m/s}^2$), these explosive impacts were highly efficient at ejecting gases. In contrast, the solar wind has a negligible long-term effect because the planet's gravity is strong enough to retain molecules energized solely by solar particles.

According to Model 1 and Model 2, which of the following statements describes a point of disagreement between the two models regarding the mechanism of atmospheric loss on Mars?

Two integers, $x$ and $y$, are positioned on a number line. The distance between $x$ and $1$ is twice the distance between $y$ and $2$. If the distance between $x$ and $y$ is exactly $5$ units, what is the sum of all possible values of $x + y$?