Secondary School (English Medium) (5 to 8) कक्षा ८ - CBSE Question Bank Solutions for Mathematics

Multiply the following: 

–7st, –1, –13st² 

Multiply the following: 

`- 100/9 rs; 3/4 r^3s^2`

Multiply the following:  

`(3/4x - 4/3 y), (2/3x + 3/2y)`

Multiply the following: 

`3/2 p^2 + 2/3 q^2, (2p^2 - 3q^2)`

The cost of a sewing machine is Rs 7,000. Its value depreciates at 8% p.a. Then the value of the machine after 2 years is Rs 5,924.80.

The value of a car, bought for Rs 4,40,000 depreciates each year by 10% of its value at the beginning of that year. So its value becomes Rs 3,08,000 after three years.

In the year 2001, the number of malaria patients admitted in the hospitals of a state was 4,375. Every year this number decreases by 8%. Find the number of patients in 2003.

The population of a town was decreasing every year due to migration, poverty and unemployment. The present population of the town is 6,31,680. Last year the migration was 4% and the year before last, it was 6%. What was the population two years ago?

The volume of a cube whose edge is 3x is ______.

A metal sheet 27 cm long, 8 cm broad and 1 cm thick is melted into a cube. The side of the cube is ______.

Three cubes of metal whose edges are 6 cm, 8 cm and 10 cm respectively are melted to form a single cube. The edge of the new cube is ______.

Two cubes have volumes in the ratio 1 : 64. The ratio of the area of a face of first cube to that of the other is ______.

A cube of side 4 cm is painted on all its sides. If it is sliced in 1 cubic cm cubes, then number of such cubes that will have exactly two of their faces painted is ______.

A cube of side 5 cm is cut into 1 cm cubes. The percentage increase in volume after such cutting is ______.

If a cube fits exactly in a cylinder with height h, then the volume of the cube is ______ and surface area of the cube is ______.

If the length of each edge of a cube is tripled, what will be the change in its volume?

How many cubes each of side 0.5 cm are required to build a cube of volume 8 cm³?

A wooden box (including the lid) has external dimensions 40 cm by 34 cm by 30 cm. If the wood is 1 cm thick, how many cm³ of wood is used in it?

What will happen to the volume of the cube, if its edge is tripled?

What will happen to the volume of the cube, if its edge is reduced to one-fourth?