IMO Level 2 Mathematics Olympiad (SOF) Class 8: Questions 1 of 315
Appeared in Year: 2012
Question
MCQ▾Which one of the following numbers is completely divisible by
Choices
Choice (4)  Response  

a. 
181560 

b. 

c. 

d. 
Answer
Explanation
Here , Where and are factors of .
So, if a number is divisible by and then it also divisible by .
And if a number is not divisible by and then it also not divisible by .
A number is divisible by 9 if the sum of the digits is divisible by 9
A number is divisible by 5 if it ends in 5 or 0
Option: A
is divisible by but it is not divisible by
It is also not divisible by .
Option: B
is divisible by but it is not divisible by
It is also not divisible by .
Option: C
is divisible by and (Sum of digits is 18 which is divisible by 5)
It is divisible by .
Option: D
is divisible by but it is not divisible by
It is also not divisible by .