Ncert Solutions For Class 7 Maths Ex 8.1

Ncert Solutions For Class 7 Maths Chapter 8 Ex 8.1

QUESTION 1:

Calculate the ratio:

            (i) Rs10 to 50 paise                      (ii) 10kg to 500g

           (iii) 60m to 20cm                          (iv) 20days to 50 hours

Solution;

(i) Rs.10 to 50 paise

=> 10 x 100 = 1000 paise            (Since , Rs.1 = 100 paise)

Thus, the ratio =  1000/50 = 20 : 1

(ii) 10kg to 500g

10 x 1000= 10000g (Since 1kg is 1000g)

Thus, the ratio = 10000/500 = 20 : 1

(iii) 60m to 20cm

60 x 100 = 6000cm (Since 1m = 100cm)

Thus, the ratio =6000/20 = 300 : 1

(iv) 20days to 50 hours

20 x 24 = 480 hours

Thus, the ratio = 480/50 = 48 : 5

 

QUESTION 2:

A computer lab has 2 computers for every 4 students. For 20 students how many computers will be required?

Solution;

Given,

4 students = 2 computers

1 student requires = 2/4 computers.

Therefore, 20 students require = (2/4) x 20 = 10 computers.

 

QUESTION 3:

Mizoram has a population of 10 lakh and Sikkim has a population of 6 lakh. Area of Mizoram is  21,000 km2 and the area of Sikkim is 7000 km2.

            (i) Find the number of people per km2 in both the states.

            (ii) Which state has a lesser population?

Solution;

(i) People per km2 = Population/ Area

In Mizoram = 1000000/21000 = 47.61 ≃48 people/km2

In Sikkim      = 600000/7000         = 85.71 ≃ 86 people/km2

(ii) Sikkim has a lesser population.

 

Related Links
10Th Cbse Maths Ncert Solutions Ncert Questions Of Science Class 10
Ncert Class 11 Biology Pdf Ncert Chemistry Class 11 Pdf Free Download
Class 11Th Maths Ncert Solutions Pdf Download Ncert Physics Class 11 Pdf Free Download
Ncert Solutions For Class 7 Maths Pdf Download Cbse Ncert Solutions For Class 7 Science
Ncert Mathematics Class 8 Solutions Ncert Of Science Class 8
Ncert Grade 9 Maths Solutions Ncert Solutions For Class 9 Chemistry