Secondary School (English Medium) (5 to 8) कक्षा ७ - CBSE Question Bank Solutions for Mathematics

[(–8) + ______] + ______ = ______ + [(–3) + ______] = –3

If x, y and z are integers then (x + ______) + z = ______ + (y + ______).

3 × (–1) × (–15) = ______.

[12 × (–7)] × 5 = ______ × [(–7) × ______]

Measurement made in science lab must be as accurate as possible. Ravi measured the length of an iron rod and said it was 19.34 cm long; Kamal said 19.25 cm; and Tabish said 19.27 cm. The correct length was 19.33 cm. How much of error was made by each of the boys?

Verify the following: 

18 × [7 + (–3)] = [18 × 7] + [18 × (–3)]

Verify the following:

(–21) × [(– 4) + (– 6)] = [(–21) × (– 4)] + [(–21) × (– 6)]

A 3 m wide path runs outside and around a rectangular park of length 125 m and breadth 65 m. Find the area of the path.

A picture is painted on a cardboard 8 cm long and 5 cm wide such that there is a margin of 1.5 cm along each of its sides. Find the total area of the margin.

A verandah of width 2.25 m is constructed all along outside a room which is 5.5 m long and 4 m wide. Find:

1) the area of the verandah

2) the cost of cementing the floor of the verandah at the rate of Rs 200 per m².

A path 1 m wide is built along the border and inside a square garden of side 30 m. Find:

1) the area of the path

2) the cost of planting grass in the remaining portion of the garden at the rate of Rs 40 per m²

Through a rectangular field of length 90 m and breadth 60 m, two roads are constructed which are parallel to the sides and cut each other at right angles through the centre of the fields. If the width of each road is 3 m, find

1)the area covered by the roads.

2) the cost of constructing the roads at the rate of Rs 110 per m².

Pragya wrapped a cord around a circular pipe of radius 4 cm (adjoining figure) and cut off the length required of the cord. Then she wrapped it around a square box of side 4 cm (also shown). Did she have any cord left? (π= 3.14)

The adjoining figure represents a rectangular lawn with a circular flower bed in the
middle. Find:

1) the area of the whole land

2) the area of the flower bed

3) the area of the lawn excluding the area of the flower bed

4)  the circumference of the flower bed.

In the following figure, find the area of the shaded portions

In the following figure, find the area of the shaded portions

Find the area of the quadrilateral ABCD.

Here, AC = 22 cm, BM = 3 cm,

DN = 3 cm, and

BM⊥AC, DN⊥AC

A rectangular park is 45 m long and 30 m wide. A path 2.5 m wide is constructed outside the park. Find the area of the path.

A path 5 m wide runs along inside a square park of side 100 m. Find the area of the path. Also, find the cost of cementing it at the rate of Rs. 250 per 10 m².

Two crossroads, each of width 5 m, run at right angles through the center of a rectangular park of length 70 m and breadth 45 m and parallel to its sides. Find the area of the roads. Also, find the cost of constructing the roads at a rate of Rs. 105 per m².