Advertisements
Advertisements
प्रश्न
Shaheed can prepare one wooden chair in 3 days and Shaif can prepare the same chair in 4 days. If they work together, in how many days will they prepare:
(i) one chair?
(ii)14 chairs of the same kind?
Advertisements
उत्तर
Shaheed's 1 day's work = `1/3`
and Shaif's 1 day's work = `1/4`
Both one day's work `= 1/3 + 1/4 = (4 + 3)/12 = 7/12`
∴ Both can prepare the chair in =`12/7` days
`= 1 5/7` days
One chair is prepared in = `1 5/7` days
∴ 14 chairs will be prepared in = `12/7 xx 14 = 24` days.
APPEARS IN
संबंधित प्रश्न
Joseph and Peter can complete a work in 20 hours and 25 hours respectively. Find :
(i) work done by both together in 4 hrs.
(ii) work left after both worked together for 4 hrs.
(iii) time taken by Peter to complete the remaining work.
A is able to complete `1/3` of a certain work in 10 hrs and B is able to complete `2/5` of the same work in 12 hrs. Find:
(i) how much work can A do in 1 hour ?
(ii) how much work can B do in 1 hour ?
(iii) in how much time will the work be completed, if both work together.
Rohit goes 350 km in 5 hours. Find:
(i) his speed
(ii) the distance covered by Rohit in 6.2 hours
(iii) the time taken by him to cover 210 km.
A boy drives his scooter with a uniform speed of 45 km/h. Find the distance covered by him in 1 hour 20 min.
A boy drives his scooter with a uniform speed of 45 km/h. Find the time taken to cover 900 m.
I travel a distance of 10 km and come back in `2 1/2` hours. What is my speed?
The speed of sound in air is about 330 ms-1. Express this speed in kmh-1. How long will the sound take to travel 99 km?
| S.No | Speed | Distance | Time (Hours) |
| i | 35 Km/hour | 280 Km | |
| ii | 40 Km/hour | 360 Km | |
| iii | 45 Km/hour | 315 Km | |
| iv | 50 Km/hour | 300 Km | |
| v | 55 Km/hour | 275 Km |
In one trip the logboat brings about 20 kg of fish. But other types of boats bring a bigger catch as given in the table. The table also shows the speed of each type of boat, which is how far each boat goes in one hour. Look at the table and calculate -
- About how far can a motorboat go in six hours?
| Type of boat | Catch of fish in one trip (in kg) |
Speed of the boat (how far it goes in one hour) |
| Log boat | 20 | 4 km per hour |
| Long tail boat | 600 | 12 km per hour |
| Motorboat | 800 | 20 km per hour |
| Machine boat | 6000 | 22 km per hour |
If a car travels at a constant speed of 45 km/h for 3 hours, what distance will it cover?
