Advertisements
Advertisements
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.
Advertisements
उत्तर
Joseph can do a work in = 20 hours
Peter can do the same work in = 25 hours
Now Joseph's 1 hour's work = `1/20`
and Peter's 1 hour's work = `1/25`
Both's 1 hour's work = `1/20 + 1/25 = (5 + 4)/100 = 9/100`
(i) Both's 4 hours work `= 9/100 xx 4 = 9/25`
(ii) Work left over `= 1 - 9/25`
`= (25 - 9)/25 = 16/25`
(iii) Peter can do `16/25` work in `= 25 xx 16/25` = 16 hours
APPEARS IN
संबंधित प्रश्न
A can do a piece of work in 6 days and B can do it in 8 days. How long will they take to complete it together?
A can do a piece of work in 4 days and B can do the same work in 5 days. Find, how much work can be done by them working together in:
- one day
- 2 days
What part of work will be left, after they have worked together for 2 days?
A train travels 700 metres in 35 seconds. What is its speed in km/h?
A boy drives his scooter with a uniform speed of 45 km/h. Find the time taken to cover 900 m.
Mr. Amit can walk 8 km in 1 hour 20 minutes. How long will it take him to walk:
(i) 2500 m?
(ii) 6.5 km?
Nazar travelled 360 Km at the speed of 90 Km/hour. Find the time taken for his travel
From where you are, what interesting things do you see to your east?
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 -
- If a long tail boat has to travel 60 km how long will it take?
| 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?
A runner covers 900 m in 3 min. Speed in m s⁻¹ is:
