NCERT Class 7 Mathematics Model Paper 2 Questions and Answers Part 4

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29. Construct a ‘XYZ if it is given that , and write steps of construction also.

Ans:

Steps:

1. Draw of length 5 cm.

2. At X draw a ray making an angle of with XY.

3. At Y draw a ray making an angle of with YX.

4. Name the point of intersection of XP and as Z.

5. is the required triangle.

30. Simplify

(i)

(ii)

(iii)

Simplify:

Ans:

(i)

(ii)

(iii)

31.

(i) What should be added to to get.

(ii) Subtract the sum of and from 10.

Ans:

(i) Let ‘k’ be added to

(ii) Sum of and

Now,

32. Out of her total monthly income, Mrs. Saxena spends 30% on house rent and 60% of the rest on household expenses. If she saves Rs. 6300 per month, what is her total monthly income?

(i) Chalk contains calcium, carbon and oxygen in the ratio 10:3: 12. Find the percentage of calcium in chalk.

(ii) If in a stick of chalk, carbon is 5 g, what is the mass of chalk stick?

Ans:

Let the total monthly income be `x

So, Amount spent on house rent = 30% of

Remaining amount left

Amount of money spent on household

Expenses = 60% of

Now, remaining income left

Since, she saves `6300

So,

Monthly income

(i) Given ratio

Total part

Part of Calcium

Percentage of calcium part in chalk

(ii) Quantity of Carbon in chalk stick = 3 g

Let the weight of chalk be x g.

Part of Carbon

Percentage of carbon part in chalk

Then, 12% of

Hence the weight of chalk stick is 25 g.