Q.69.

[Manish Salian]

Hi All,

Today is 9/11! Its been 5 years since the terror Tuesday, but its ghost is still haunting us...

For a change, I have picked up a piece of history for all of you!

Which historical event took place on 9/11 that played an important role in India's freedom struggle?

History books . . . . Google . . . . here I come!

Here is interesting math on properties of 9 and 11:

Q.69.

What property is displayed by numbers divisible by 9 or by 11? Interestingly, both the properties are similar to each other!


I am yet to reveal the answers to Q.71 and Q.70. The scores so far are:

Minnat: 18 points
Anil: 17 points
Abhinav: 4 points
Nisha: 5 ponits :confused:

Regards,

Manish sir

[AnilkumarBDaga]

Hello Sir,

Any number which is divisible by 9 or 11 will also be divisible - if a new number is formed by reversing the digits.

example 189 and 981 are both divisible by 9.
example 231 and 132 are both divisible by 11.

Thanks & Regards,
Anil Daga
:)

[Manish Salian]

Hi Anil,

You are absolutely right! That is indeed the property that I was looking for. Both, numbers divisible by 9 and 11 remain divisible by them respectively even if they are reversed!

Also, if you add single digits of a number divisible by 9, you get another number divisible by 9. For eg. 17244 is divisible by 9 because 1 + 7 + 2 + 4 + 4 = 18 which is divisible by 9 (you knew this property, right?)

The same property extends to number divisible by 11, but for the fact that you need to add two-digits at a time from right-end!

For example, 137467 is divisible by 11. If if then add its digits taking two at a time from right-end viz: 67 + 74 +13 = 154, which is a number divisible by 11.

You get 5 points for this question, Anil!

Regards,

Manish sir

[AbhinavSingh]

late as usual,
searched a lot on the net, racked my brains, consulted a lotta frnds.......finally i get it and the answer is alraedy there.hopefully, i will get 2 deserving pts for my efforts......sir, u8 r the judge.

abhinav