Question : The Least Common Multiple of three different numbers is 40. Which of the following cannot be their Highest Common Factor?
Option 1: 20
Option 2: 25
Option 3: 5
Option 4: 10
Correct Answer: 25
Solution :
Given: The Least Common Multiple of three different numbers is 40.
The HCF of those numbers must be a factor of that LCM too.
From the given options only 25 is not a factor of 40.
So, 25 can't be the HCF.
Hence, the correct answer is 25.