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

Verify the property x × (y × z) = (x × y) × z of rational numbers by using

`x = (-2)/7, y = (-5)/6` and `z = 1/4`

and What is the name of this property?

Tell which property allows you to compare

`2/3 xx [3/4 xx 5/7]` and `[2/3 xx 5/7] xx 3/4`

Name the property used in the following.

`1/3 + [4/9 + ((-4)/3)] = [1/3 + 4/9] + [(-4)/3]`

If one member of a pythagorean triplet is 2m, then the other two members are ______.

The sum of successive odd numbers 1, 3, 5, 7, 9, 11, 13 and 15 is ______.

The sum of first n odd natural numbers is ______.

The hypotenuse of a right triangle with its legs of lengths 3x × 4x is ______.

If m is the square of a natural number n, then n is ______.

There are ______ natural numbers between n² and (n + 1)² 

The sides of a right triangle whose hypotenuse is 17 cm are ______ and ______.

The least number by which 72 be multiplied to make it a perfect cube is ______.

The least number by which 72 be divided to make it a perfect cube is ______.

The sum of two perfect squares is a perfect square.

Each prime factor appears 3 times in its cube.

For every natural number m, (2m – 1, 2m² – 2m, 2m² – 2m + 1) is a pythagorean triplet.

All numbers of a pythagorean triplet are odd.

If x and y are integers such that x² > y², then x³ > y³.

Using prime factorisation, find which of the following are perfect cubes.

128

Using prime factorisation, find which of the following are perfect cubes.

343

Using prime factorisation, find which of the following are perfect cubes.

729