Q12 of 55 Page 61

I am the smallest number, having four different prime factors. Can you find me?

As it is the smallest number, it will be the product of 4 smallest prime numbers;


2 × 3 × 5 × 7 = 210.


More from this chapter

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10

Determine if 25110 is divisible by 45.

 11

18 is divisible by both 2 and 3. It is also divisible by 2 × 3 = 6. Similarly, a number is divisible by both 4 and 6. Can we say that the number must also be divisible by 4 × 6 = 24? If not, give an example to justify your answer.

 1

Find the HCF of the following numbers:

(a) 18, 48 (b) 30, 42


(c) 18, 60 (d) 27, 63


(e) 36, 84 (f) 34, 102


(g) 70, 105, 175


(h) 91, 112, 49 (i) 18, 54, 81


(j) 12. 45. 75

 2

What is the HCF of two consecutive-

(a) numbers?


(b) even numbers?


(c) odd numbers?