Complete the following statements with suitable word(s).
1. Probability of an event E + Probability of the event ‘not E’ = _______ .
2. The probability of an event that cannot happen is ________ . Such an event is called ___________ .
3. The probability of an event that is certain to happen is ________ . Such an event is called ___________ .
Q1: The word ‘Economics’ originates from the ________ world ‘Oikonomia’
(a) Roman
(b) French
(c) Greek
(d) European
Q2: In Business economics ‘ends’ refers to-
(a) Human wants
(b) Resources
(c) Both (a) and (b)
(d) none of these
 |
| Image Credits: Tomáš Kebert & umimeto.org (wikimedia) |
Fill in the blanks with suitable words.
1. Soil is formed by the breaking down of rocks, by the action of wind, water and climate, called __________.
2. The removal of land surface by water, wind or ice is known as ________.
3. ________ soil having organic matter and a good capacity to retain water are ideal sources for growing paddy.
Fill in the blanks with suitable word(s).
1. Numbers having more than two factors are called _____________ numbers.
2. A _______ of a number is an exact divisor of that number.
3. ______ is a factor of every number.
Cube root is the inverse operation of a cube.
Symbol ∛ represents a cube-root.
e.g. $\sqrt[3]{8} = 2$,
$\sqrt[3]{216} = 6$
METHODS OF FINDING CUBE ROOT
There are two methods of finding Cube Root
1. Prime Factorisation
2. Estimation Method
Q1: Which of the following statements is wrong for viroids?
(a) They cause infections.
(b) Their RNA is of high molecular weight.
(c) They lack a protein coat.
(d) They are smaller than viruses.
Class 9 Maths - Important Identities
(a+b)² = a² + 2ab+ b²
(a–b)² = a² –2ab + b²
a² – b² = (a+b)(a–b)
