Science (English Medium) Class 11 - CBSE Question Bank Solutions

Check the validity of the following statement.
q: 131 is a multiple of 3 or 11

Which of the following is a statement?

Which of the following is not a statement>

The connective in the statement “2 + 7 > 9 or 2 + 7 < 9” is ______.

The connective in the statement “Earth revolves round the Sun and Moon is a satellite of earth” is ______.

The negation of the statement “A circle is an ellipse” is ______.

The negation of the statement “7 is greater than 8” is ______.

The negation of the statement “72 is divisible by 2 and 3” is ______.

The negation of the statement “Plants take in CO₂ and give out O₂ ” is ______.

The negation of the statement “Rajesh or Rajni lived in Bangalore” is ______.

The negation of the statement “101 is not a multiple of 3” is ______.

Which of the following is the conditional p → q?

The negation of the statement “The product of 3 and 4 is 9” is ______.

Which of the following is not a negation of “A natural number is greater than zero”?

Which of the following statement is a conjunction?

State whether the following sentences are statements are not.
(i) The angles opposite to equal sides of a triangle are equal.
(ii) The moon is a satellite of earth.
(iii) May God bless you!
(iv) Asia is a continent.
(v) How are you?

Show that the two formulae for the standard deviation of ungrouped data.

`sigma = sqrt((x_i - barx)^2/n)` and `sigma`' = `sqrt((x^2_i)/n - barx^2)` are equivalent.

Life of bulbs produced by two factories A and B are given below:

The bulbs of which factory are more consistent from the point of view of length of life?

A set of n values x₁, x₂, ..., x_n has standard deviation 6. The standard deviation of n values x₁ + k, x₂ + k, ..., x_n + k will be ______.

Find the standard deviation of the first n natural numbers.