Advertisements
Advertisements
Question
Mohit can complete a work in 50 days, whereas Anuj can complete the same work in 40 days. Find:
(i) work done by Mohit in 20 days.
(ii) work left after Mohit has worked on it for 20 days.
(iii) time taken by Anuj to complete the remaining work.
Advertisements
Solution
Mohit can complete a work in 50 days
and Anuj can complete the same work in 40 days
∴ Mohit's one day's work = `1/50`
and Anuj's one day's work =`1/40`
(i) Mohit's 20 day's work = `1/50 xx 20 = 2/5`
(ii) Work left = `1 - 2/5 = (5 - 2)/5 = 3/5`
Anuj can do `3/5` work in = `40xx3/5` days = 24 days
APPEARS IN
RELATED QUESTIONS
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?
A, B and C can do a piece of work in 12, 15 and 20 days respectively. How long will they take to do it working 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.
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?
Nazar travelled 360 Km at the speed of 90 Km/hour. Find the time taken for his travel
These log boats do not go very far. If the wind is helpful, then travel about 4 km in one hour.
Guess how far you can go in one hour if you walk fast.
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 |
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 |
The SI unit of speed is:
A runner covers 900 m in 3 min. Speed in m s⁻¹ is:
