Getting inspired too much!

Find the sum of all 2 digit numbers when flipped and added together result in a perfect square.


The answer is 484.

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

1 solution

Chew-Seong Cheong
Oct 29, 2015

Let the required two-digit number n = 10 a + b n = 10a + b , where a , b = 1 , 2 , 3 , . . . 9 a,b = 1,2,3,...9 . Then, we have:

10 a + b + 10 b + a = 11 ( a + b ) = m 2 10a+b + 10b+a = 11(a+b) = m^2 , where m m is a positive integer. For 11 ( a + b ) 11(a+b) to be a perfect square, a + b a+b must be 11 11 . All the possible cases and their sum are as follows:

\[\begin{array} {} 29 &+ & 92& =& 121 \\ 38&+&83&=&121 \\ 47&+&74&=&121 \\ 56&+&65&=&121 \\ \hline &&&& \boxed{484} \end{array} \]

Same way! Answer is another perfect square :)

Arulx Z - 5 years, 7 months ago

Exactly Same Way

Kushagra Sahni - 5 years, 7 months ago

Log in to reply

Do you remember, you reshare a similar problem?

Dev Sharma - 5 years, 7 months ago

Log in to reply

Yes I do, I did it on Tuesday.

Kushagra Sahni - 5 years, 7 months ago

Log in to reply

@Kushagra Sahni Keep it up!!

Dev Sharma - 5 years, 7 months ago

Log in to reply

@Dev Sharma Today is my NMTC Final exam. I am very nervous.

Kushagra Sahni - 5 years, 7 months ago

Log in to reply

@Kushagra Sahni Best of luck. How can i participate?

Dev Sharma - 5 years, 7 months ago

Log in to reply

@Dev Sharma You first need to clear stage 1 of it. To appear for stage-1 ask your school about it next year or maybe you will join a coaching institute so you can appear for it from there.

Kushagra Sahni - 5 years, 7 months ago

Log in to reply

@Kushagra Sahni oh.. Tell me when would you be active on fb? Because moderators don't allow us to chat her

Dev Sharma - 5 years, 7 months ago

Log in to reply

@Dev Sharma On Monday Afternoon write hi to me i will come

Kushagra Sahni - 5 years, 7 months ago

Log in to reply

@Kushagra Sahni how was your exam? Share a note of all problems.

Dev Sharma - 5 years, 7 months ago

Log in to reply

@Dev Sharma It was absolutely horrible .

Kushagra Sahni - 5 years, 7 months ago

Log in to reply

@Kushagra Sahni I know you have got most problems correct. Please share a note about problems and your experience.

Dev Sharma - 5 years, 7 months ago

Log in to reply

@Dev Sharma No seriously It was extremely difficult all intelligent kids in my batch also found it extremely tough. I will show you the questions tomorrow.

Kushagra Sahni - 5 years, 7 months ago

Log in to reply

@Kushagra Sahni Thanks. I would WAIT

Dev Sharma - 5 years, 7 months ago

Log in to reply

@Dev Sharma I will upload a note of all the questions by tomorrow

Satyajit Ghosh - 5 years, 7 months ago

Log in to reply

@Satyajit Ghosh i would wait.

Dev Sharma - 5 years, 7 months ago

@Kushagra Sahni hey ??????

Dev Sharma - 5 years, 7 months ago

Perfect solution.

Dev Sharma - 5 years, 7 months ago

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...