Advertisements
Advertisements
प्रश्न
A number when decreased by 20% gives 80. Find the number
उत्तर
Let the number be x.
Given that when it is increased by 20% we get 80.
`x - 20/100 xx x` = 80
`(100x - 20x)/100` = 80
`(80x)/100` = 80
⇒ x = `(80 xx 100)/80`
x = 100
APPEARS IN
संबंधित प्रश्न
Express the following as decimal fractions:
27%
An alloy of tin and copper consists of 15 parts of tin and 105 parts of copper. Find the percentage of copper in the alloy?
An alloy contains 32% copper, 40% nickel and rest zinc. Find the mass of the zinc in 1 kg of the alloy.
A number 3.625 is wrongly read as 3.265; find the percentage error.
A bag contains 8 red balls, 11 blue balls and 6 green balls. Find the percentage of blue balls in the bag.
What percent is: 16 hours of 2 days?
Find the value of: 5% of Rs. 350
Find the value of `33 1/3 %` of 27 m
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.
If the difference between 75% of a number and 60% of the same number is 82.5, then find 20% of that number
