Advertisements
Advertisements
प्रश्न
A cistern can be filled by one tap in 8 hours, and by another in 4 hours. How long will it take to fill the cistern if both taps are opened together?
Advertisements
उत्तर
\[\text{ Time taken by the first tap to fill the cistern = 8 hours } \]
\[\text{ Time taken by the second tap to fill the cistern = 4 hours } \]
\[ \therefore \text{ Work done by the first tap in 1 hour } = \frac{1}{8}\]
\[ \text{ Work done by the second tap in 1 hour } = \frac{1}{4}\]
\[ \therefore \text{ Work done by both the taps in 1 hour } = \frac{1}{8} + \frac{1}{4}\]
\[ = \frac{1 + 2}{8} = \frac{3}{8}\]
\[\text{ Thus, both the taps together will fill the cistern in } \frac{8}{3} \text{ hours or } 2\frac{2}{3} \text{ hours } .\]
APPEARS IN
संबंधित प्रश्न
Sita can finish typing a 100 page document in 9 hours. Mita in 6 hours and Rita in 12 hours. How long will they take to type a 100 page document if they work together?
Aasheesh can paint his doll in 20 minutes and his sister Chinki can do so in 25 minutes. They paint the doll together for five minutes. At this juncture they have a quarrel and Chinki withdraws from painting. In how many minutes will Aasheesh finish the painting of the remaining doll?
- How far will it travel in 20 minutes?
- Find the time required to cover a distance of 250 km.
If the cost of 3 books is ₹ 90, then find the cost of 12 books.
100 persons had food provision for 24 days. If 20 persons left the place, the provision will last for ______.
Both x and y vary directly with each other and when x is 10, y is 14, which of the following is not a possible pair of corresponding values of x and y?
In direct proportion, `a_1/b_1` ______ `a_2/b_2`
Write whether the following statement vary directly, vary inversely with each other, or neither of the two.
Number of students in a hostel and consumption of food.
Campus and Welfare Committee of school is planning to develop a blue shade for painting the entire school building. For this purpose various shades are tried by mixing containers of blue paint and white paint. In the following mixtures, decide which is a lighter shade of blue and also find the lightest blue shade among all of them.
| Mixture A | Mixture B |
 |
 |
If one container has one litre paint and the building requires 105 litres for painting, how many container of each type is required to paint the building by darkest blue shade?
Here is a key board of a harmonium:
- Find the ratio of white keys to black keys on the keyboard.
- What is the ratio of black keys to all keys on the given keyboard.
- This pattern of keys is repeated on larger keyboard. How many black keys would you expect to find on a keyboard with 14 such patterns.
