Advertisements
Advertisements
Question
Air is an important inexhaustible natural resource. It is essential for the survival of human beings, microbes, plants, and animals. The following table shows the percentage of various gases in the air.
| Contents of air | Percentage (by volume) |
| Nitrogen | 78 |
| Oxygen | 21 |
| Other (carbon dioxide, inert gases, water vapours, etc.) | 1 |
In 800 m3 of air, calculate the approximate quantities of nitrogen, oxygen, and other gases.
Advertisements
Solution
Nitrogen in air = 78%, Oxygen = 21%, Others = 1%
Quantity of air = 800 m3
∴ Quantity of nitrogen in it = 800 of 78%
= `800xx78/100"m"^3`
= 624 m3
∴ Quantity of oxygen = 800 of 21%
= `800xx21/100"m"^3`
= 168 m3
∴ Quantity of other gases = 800 of 1%
= `800xx1/100"m"^3`
= 8 m3
APPEARS IN
RELATED QUESTIONS
Deepti went to school for 216 days in a full year. If her attendance is 90%, find the number of days on which the school was opened.
Find the percentage change, when a number is changed from :
6.25 to 7.50
A number when decreased by 16% becomes 798 ; find the number.
A girl got 375 marks out of 500 in the first term examination, 560 marks out of 800 in the second term examination, and 840 marks out of 1200 in the third term examination. Find:
(i) her percentage score in the first term examination.
(ii) her percentage score in the second term examination.
(iii) her percentage score in the third term examination.
(iv) the total marks secured in all the three examinations.
(v) the total marks scored in all the three examinations.
(vi) her percentage score on the whole in all three examinations.
The price of an article increased from ₹ 16 to ₹ 20; find the percentage increase.
Air is an important inexhaustible natural resource. It is essential for the survival of human beings, microbes, plants, and animals. The following table shows the percentage of various gases in the air.
| Contents of air | Percentage (by volume) |
| Nitrogen | 78 |
| Oxygen | 21 |
| Other (carbon dioxide, inert gases, water vapours, etc.) | 1 |
If a certain quantity (by volume) of air contains 4,200 litres of oxygen, find the total quantity of air taken and the amount of nitrogen in it.
Out of total 120 teachers of a school 70 were male. Express the number of male teachers as percentage
An average urban Indian uses about 150 litres of water every day.
| Activity | Litres per person per day |
| Drinking | 3 |
| Cooking | 4 |
| Bathing | 20 |
| Sanitation | 40 |
| Washing clothes | 40 |
| Washing utensils | 20 |
| Gardening | 23 |
| Total | 150 |
What per cent of water is used for drinking, cooking and gardening together?
5.2 is equal to ______.
In an examination, there are three papers each of 100 marks. A candidate obtained 53 marks in the first and 75 marks in the second paper. How many marks must the candidate obtain in the third paper to get an overall of 70 per cent marks?
