Background: As shown here, pressure decreases to less than 25% of ground-level atmospheric pressure when we get to an altitude of about six miles. Since this is a common cruising altitude for commercial airplanes, pressurized cabins are needed for the comfort and survival of the passengers. This is because the density of the air decreases along with the decreasing air pressure, so there is less oxygen in a breath of air. You've probably noticed this effect in high-mountain areas, as it often feels harder to breath.

Situation: John likes to ride on hot air balloon. Last month he rode on a balloon with his friend Keith. First they were at the ground-level. They called it camp A. Then they rose to the height of three miles. They called it camp B. Eventually, they reached six miles above ground. They called it camp C.

Question: Where the air would be denser, camp A or camp B?
Answer: camp A

Situation: John likes to ride on hot air balloon. Last month he rode on a balloon with his friend Keith. First they were at the ground-level. They called it camp A. Then they rose to the height of three miles. They called it camp B. Eventually, they reached six miles above ground. They called it camp C.

Question: Where the air would be thinner, camp A or camp B?
Answer: camp B

Situation: John likes to ride on hot air balloon. Last month he rode on a balloon with his friend Keith. First they were at the ground-level. They called it camp A. Then they rose to the height of three miles. They called it camp B. Eventually, they reached six miles above ground. They called it camp C.

Question: Would the air be denser or thinner at camp B than at camp C?
Answer: denser

Situation: John likes to ride on hot air balloon. Last month he rode on a balloon with his friend Keith. First they were at the ground-level. They called it camp A. Then they rose to the height of three miles. They called it camp B. Eventually, they reached six miles above ground. They called it camp C.

Question: Would the air be denser or thinner at camp C than at camp B?
Answer: thinner

Situation: John likes to ride on hot air balloon. Last month he rode on a balloon with his friend Keith. First they were at the ground-level. They called it camp A. Then they rose to the height of three miles. They called it camp B. Eventually, they reached six miles above ground. They called it camp C.

Question: Which place would have more oxygen, camp A or camp B?
Answer: camp A

Situation: John likes to ride on hot air balloon. Last month he rode on a balloon with his friend Keith. First they were at the ground-level. They called it camp A. Then they rose to the height of three miles. They called it camp B. Eventually, they reached six miles above ground. They called it camp C.

Question: Which place would have less oxygen, camp A or camp B?
Answer: camp B

Situation: John likes to ride on hot air balloon. Last month he rode on a balloon with his friend Keith. First they were at the ground-level. They called it camp A. Then they rose to the height of three miles. They called it camp B. Eventually, they reached six miles above ground. They called it camp C.

Question: Would there be less or more oxygen in camp B than in camp C?
Answer: more

Situation: John likes to ride on hot air balloon. Last month he rode on a balloon with his friend Keith. First they were at the ground-level. They called it camp A. Then they rose to the height of three miles. They called it camp B. Eventually, they reached six miles above ground. They called it camp C.

Question: Would there be less or more oxygen in camp C than in camp B?
Answer: less

Situation: John likes to ride on hot air balloon. Last month he rode on a balloon with his friend Keith. First they were at the ground-level. They called it camp A. Then they rose to the height of three miles. They called it camp B. Eventually, they reached six miles above ground. They called it camp C.

Question: In which place John and Keith would find it harder to breath, camp A or camp C?
Answer: camp C

Situation: John likes to ride on hot air balloon. Last month he rode on a balloon with his friend Keith. First they were at the ground-level. They called it camp A. Then they rose to the height of three miles. They called it camp B. Eventually, they reached six miles above ground. They called it camp C.

Question: In which place John and Keith would find it easier to breath, camp A or camp C?
Answer: camp A

Situation: John wanted to see how he would fare in high altitude compared to ground-level. So, he first measured his responses in ground-level. He labeled this part of the study as case A. Then he board on an airplane to reach high altitude, and measured his responses there. He labeled this part of the study as case B. Now, John knows how he needs to prepare for a high altitude hiking.

Question: Which case would see higher atmospheric pressure, case A or case B?
Answer: case A

Situation: John wanted to see how he would fare in high altitude compared to ground-level. So, he first measured his responses in ground-level. He labeled this part of the study as case A. Then he board on an airplane to reach high altitude, and measured his responses there. He labeled this part of the study as case B. Now, John knows how he needs to prepare for a high altitude hiking.

Question: Which case would see lower atmospheric pressure, case A or case B?
Answer: case B

Situation: John wanted to see how he would fare in high altitude compared to ground-level. So, he first measured his responses in ground-level. He labeled this part of the study as case A. Then he board on an airplane to reach high altitude, and measured his responses there. He labeled this part of the study as case B. Now, John knows how he needs to prepare for a high altitude hiking.

Question: Would case A see higher or lower atmospheric pressure than case B?
Answer: higher

Situation: John wanted to see how he would fare in high altitude compared to ground-level. So, he first measured his responses in ground-level. He labeled this part of the study as case A. Then he board on an airplane to reach high altitude, and measured his responses there. He labeled this part of the study as case B. Now, John knows how he needs to prepare for a high altitude hiking.

Question: Would case B see higher or lower atmospheric pressure than case A?
Answer: lower

Situation: John wanted to see how he would fare in high altitude compared to ground-level. So, he first measured his responses in ground-level. He labeled this part of the study as case A. Then he board on an airplane to reach high altitude, and measured his responses there. He labeled this part of the study as case B. Now, John knows how he needs to prepare for a high altitude hiking.

Question: Which case would see higher air density, case A or case B?
Answer: case A

Situation: John wanted to see how he would fare in high altitude compared to ground-level. So, he first measured his responses in ground-level. He labeled this part of the study as case A. Then he board on an airplane to reach high altitude, and measured his responses there. He labeled this part of the study as case B. Now, John knows how he needs to prepare for a high altitude hiking.

Question: Which case would see lower air density, case A or case B?
Answer: case B

Situation: John wanted to see how he would fare in high altitude compared to ground-level. So, he first measured his responses in ground-level. He labeled this part of the study as case A. Then he board on an airplane to reach high altitude, and measured his responses there. He labeled this part of the study as case B. Now, John knows how he needs to prepare for a high altitude hiking.

Question: Would case A see higher or lower air density than case B?
Answer: higher

Situation: John wanted to see how he would fare in high altitude compared to ground-level. So, he first measured his responses in ground-level. He labeled this part of the study as case A. Then he board on an airplane to reach high altitude, and measured his responses there. He labeled this part of the study as case B. Now, John knows how he needs to prepare for a high altitude hiking.

Question: Would case B see higher or lower air density than case A?
Answer: lower

Situation: John wanted to see how he would fare in high altitude compared to ground-level. So, he first measured his responses in ground-level. He labeled this part of the study as case A. Then he board on an airplane to reach high altitude, and measured his responses there. He labeled this part of the study as case B. Now, John knows how he needs to prepare for a high altitude hiking.

Question: Which case would see less oxygen, case A or case B?
Answer: case B

Situation: John wanted to see how he would fare in high altitude compared to ground-level. So, he first measured his responses in ground-level. He labeled this part of the study as case A. Then he board on an airplane to reach high altitude, and measured his responses there. He labeled this part of the study as case B. Now, John knows how he needs to prepare for a high altitude hiking.

Question: Which case would see more oxygen, case A or case B?
Answer: case A