हिंदी
सी.आई.एस.सी.ई.आईसीएसई ICSE Class 7

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.

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?

योग
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`

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 8: Unitary Method (Including Time and Work) - Exercise 7 (C)

APPEARS IN

आर.के. बंसल Concise Mathematics [English] Class 7 ICSE
अध्याय 8 Unitary Method (Including Time and Work)
Exercise 7 (C) | Q 4

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, B and C together finish a work in 4 days. If A alone can finish the same work in 8 days and B in 12 days, find how long will C take to finish the work.


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 time taken by him to cover 108 km.


Jagan went to another town such that he covered 240 km by a car going at 60 kmh-1. Then he covered 80 km by a train, going at 100 kmh-1 and the rest 200 km, he covered by a bus, going at 50 kmh-1. What was his average speed during the whole journey?


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?


Name two things that are lying to your west.


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 -

  • 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

Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×