Advertisements
Advertisements
प्रश्न
A and B take 6 hours and 9 hours respectively to complete a work. A works for 1 hour and then B works for two hours.
(i) How much work is done in these 3 hours?
(ii) How much work is still left?
Advertisements
उत्तर
A takes 6 hours to finish work
and B take 9 hours to finish the same work
∴ A's 1 hour's work = `1/6`
and B's 1 hour's work = `1/9`
and B's 2 hours work =`1/9 xx 2= 2/9`
(i) Now A's 1 hours work + B's 2 hours work
`= 1/6 + 2/9 = (3 + 4)/18 = 7/18`
(ii) Work left = `1 - 7/18 = (18 - 7)/18 = 11/18`
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 train travels 700 metres in 35 seconds. What is its speed in km/h?
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.
| 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 |
Nazar travelled 360 Km at the speed of 90 Km/hour. Find the time taken for his travel
Fathima reached 480 Km at the speed of 120 Km/hour. How much time did she travelled?
Look at the different types of boats.
Some boats have motors and go further into the sea. since they go far out they can catch more fish. These boats travel faster, at a speed of about 20 km in one hour.
How far would the motorboats go in three and a half hours?
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 much fish in all will each type of boat bring in seven trips?
| 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 |
