Which of the following statements is not true ?

Correct option is D

The statement that is not true is (d) HCF and LCM of two numbers x and y can be respectively 16 and 196.
The HCF (Highest Common Factor) is the largest positive integer that is a factor of both x and y. The LCM (Least Common Multiple) is the smallest positive integer that is a multiple of both x and y.
For the HCF and LCM to be 16 and 196, respectively, both x and y must be multiples of 16. However, 196 is not a multiple of 16. Therefore, it is not possible for the HCF and LCM of two numbers to be 16 and 196, respectively.
The other three statements are all true. For example, the HCF and LCM of 28 and 84 are 28 and 84, respectively. The HCF and LCM of 15 and 7 are 1 and 105, respectively. And the HCF and LCM of 30 and 30 are 150 and 900, respectively.