CBSE Guess > Papers > Important Questions > Class XI > 2010 > Maths > Maths By Mr. Anil Kumar Tondak
CBSE CLASS XI
**Mathematical Reasoning**
**Q.1.** Write the negation of the following statements:
(i) The number 2 is greater than 7.
(ii) All triangles are not equilateral triangle.
(iii) Australia is a continent.
(iv) There does not exist a quadrilateral which has all its sides equal.
(v) Every natural number is greater than 0.
(vi) The sum of 3 and 4 is 9.
**Q.2**. Find the component statements of the following compound statements and check
whether they are true or false.
(i) Number 3 is prime or it is odd.
(ii) All integers are positive or negative.
(iii) 100 is divisible by 3, 11 and 5.
**Q.3.** State whether the “Or” used in the following statements is “exclusive “or” inclusive.
Give reasons for your answer.
(i) Sun rises or Moon sets.
(ii) To apply for a driving licence, you should have a ration card or a passport.
(iii) All integers are positive or negative.
**Q.4.** Write the contrapositive of the following statements :
(i) If a triangle is equilateral, it is isosceles.
(ii) If is a prime number, then is odd.
**Q.5.** Write the converse of the following statements.
(i) If a number *n *is even, then *n*2 is even.
(ii) If you do all the exercises in the book, you get an A grade in the class.
(iii) If two integers *a *and *b *are such that *a *> *b*, then *a *– *b *is always a positive integer.
**Q. 6.** Check whether the following statement is true or not.
If
**Q.7.** Using the words “necessary and sufficient” rewrite the statement
“the integer n is odd if and only if n2 is odd”. Also check whether the statement is true.
**Q.8. **Rewrite the following statements in the form of “p if and only if q”.
(i) p : If you watch television, then you mind is free and if your mind is free, then you watch television.
(ii) q : For you to get an A grade, it is necessary and sufficient that you do all the homework regularly
Paper By Mr. Anil Kumar Tondak
Email Id : [email protected]
Ph No.: 9811363962 |