Page 161 - Ganit Kaushal

4. 2 is neither a prime nor a composite number.

5. A number divisible by two co-prime numbers is always divisible by their product.
6. Prime factorisation of a number is not unique.

7. Factorisation of a number is not unique.
8. If a number divides the sum of two numbers, then it must divide the two numbers separately.

IV. Solve the following questions.
1. Determine whether the following numbers are divisible by 4, 8 and 5.

(a) 197244 (b) 613440 (c) 4100448
2. Write all possible natural numbers formed by the digits 7, 0, and 3. Repetition of digits is not allowed.
3. Find the prime factorisation of the following numbers.

(a) 168 (b) 2304
4. Children are playing the game ‘Dahi-Vada’ with two numbers, 2 and 7. Write the first 15 numbers
when children say ‘Dahi-Vada’.

5. Match the items in Column I with the items in Column II.
Column I Column II

(a) 35 (i) Multiple of 8
(b) 15 (ii) Multiple of 7
(c) 16 (iii) Multiple of 70

(d) 20 (iv) Factor of 30
(e) 25 (v) Factor of 50
(vi) Factor of 20

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