Advertisements
Advertisements
प्रश्न
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.
Advertisements
उत्तर
Nitrogen in air = 78%, Oxygen = 21%, Others = 1%
If the air contains 4200 litres of oxygen, then the total quantity of air
= `(4200xx100)/21` litres
= 200 × 100 litres
= 20000 litres
and the amount of nitrogen in it = 20000 of 78%
= `20000xx78/100`
= 15600 litres
APPEARS IN
संबंधित प्रश्न
A cricketer hit 120 runs in 150 balls during a test match. 20% of the runs came in 6's, 30% in 4's, 25% in 2's and the rest in 1's. How many runs did he score in
(i) 6's
(ii) 4's
(iii) 2's
(iv) singles
What % of his shots were scoring ones?
Find the percentage change, when a number is changed from :
80 to 100
A number 5.78 x 103 is wrongly written as 5.87 x 103; find the percentage error
The cost of an article is first increased by 20% and then decreased by 30%, find the percentage change in the cost of the article.
Express the following percentage as a fraction and as a decimal number:
25 %
Find the resulting quantity when there is a 2.5% increase in the salary of ₹ 62,500.
A student gets 31% marks in an examination but fails by 12 marks. If the pass percentage is 35%, find the maximum marks of the examination.
A student earned a grade of 80% on a math test that had 20 problems. How many problems on this test did the student answer correctly?
Find the value of x if 45% of marks x is 405.
Imagine that a 10 × 10 grid has value 300 and that this value is divided evenly among the small squares. In other words, each small square is worth 3. Use a new grid for each part of this problem, and label each grid “Value: 300.”
- Shade 25% of the grid. What is 25% of 300? Compare the two answers.
- What is the value of 25 squares?
- Shade 17% of the grid. What is 17% of 300? Compare the two answers
- What is the value of `1/10` of the grid?
- Express `1/6` as a percent.
