Page 70 - Math_Genius_V1.0_C5_Flipbook

E:\Working\Focus_Learning\Math_Genius_5_(05-10-2023)\Open_Files\CHAP_03
\\February 16, 2024 2:20 PM Surender Prajapati Proof 5 Reader _________________________ Date: ___________________74

Practice time 3d

1. State whether the following statements are a 'true' or 'False'.

(a) A prime number has more than 2 factors.

(b) 1 is a composite number.

(c) 2 is the only even prime number.
(d) 97 is the greatest 2-digit prime number.

(e) 1 is the smallest prime number.
(f) 47 is a composite number.

2. Fill in the blanks.

(a) ______________ is the only prime number between 90 and 100.

(b) ______________ is the smallest and only even prime number.

(c) There are ______________ prime numbers between 1 and 100.

(d) The prime factors of 32 are ______________.

(e) _____________ is the smallest odd composite number.
3. Find the prime factors of the following numbers using factor tree method.

(a) 18 (b) 28 (c) 32 (d) 40

(e) 64 (f) 90 (g) 78 (h) 120
4. Find the prime factors of the following numbers using the prime factorisation
method. draw the factor tree for each.

(a) 27 (b) 48 (c) 54 (d) 63

(e) 78 (f) 91 (g) 65 (h) 96

(i) 8 (j) 112 (k) 125 (l) 144

HigHest common factor (Hcf)

Let us consider any two numbers, say 12 and 18.
List all factors of 12 and 18.
FACTS
Factors of 12 are 1, 2, 3, 4, 6 and 12. A common factor is a
Factors of 18 are 1, 2, 3, 6, 9 and 18. number which is a factor of

Common factors of 12 and 18 are 1, 2, 3 and 6. two or more numbers.

Highest common factor (HCF) of 12 and 18 is 6.
Thus, highest common factor (HCF) of two or more numbers is the greatest number that

divides each given number exactly.

68 Mathematics-5