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

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:

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?

योग
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.

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

APPEARS IN

सेलिना Concise Mathematics [English] Class 7 ICSE
अध्याय 7 Unitary Method (Including Time and Work)
Exercise 7 (C) | Q 10

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?


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, 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.


A train covers 51 km in 3 hours. Calculate its speed. How far does the train go in 30 minutes?


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?


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

What is the correct relationship between speed (S), distance (D), and time (T)?


The SI unit of speed is:


If a car travels at a constant speed of 45 km/h for 3 hours, what distance will it cover?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×