Author Archives: nkpithwa

I am a DSP Engineer and a mathematician working in closely related areas of DSP, Digital Control, Digital Comm and Error Control Coding. I have a passion for both Pure and Applied Mathematics.

Announcement: Tenth Statistics Olympiad 2018 :-) :-) :-)

Here’s to Statistics with love !

Nalin Pithwa.


The Association of Mathematics Teachers of India

(I found this v nice organization and the list of its v cheap, high quality publications in Math for kids in a blog of Mr. Gaurish Korpal.)

Quite frankly, these mathematics teachers are doing/have done profound service to India’s budding, aspiring generations of child mathematicians!! 🙂 And, also to many parents in India, who mostly (in my personal opinion) think of only law, engineering, and medicine as the only respectable professions…:-( like Professor “Virus” of the famous movie, Three Idiots ! 🙂

Hats off to AMTI !!!

Nalin Pithwa.

Childhood Maths — Gaurish Korpal’s blog

Inspirational to all kids, and hopefully, educative to Indian parents also, if I may add…

Thanks Mr. Gaurish Korpal.

from Nalin Pithwa.

How to deal with failure

via How to deal with failure?

Why study geometry? An answer from Prof. Gangsong Leng


Geometric Inequalities, Vol 12, Mathematical Olympiad Series, Gangsong Leng, translated by Yongming Liu, East China Normal University Press, World Scientific.

“God is always doing geometry”, said Plato. But, the deep investigation and extensive attention to geometric inequalities as an independent field is a matter of modern times.

Many geometric inequalities are not only typical examples of mathematical beauty but also tools for applications as well. The well known Brunn-Minkowski’s inequality is such an example. “It is like a large octopus, whose tentacles stretches out into almost every field of mathematics. It has not only relation with advanced mathematics such as the Hodge index theorem in algebraic geometry, but also plays an important role in applied subjects such as stereology, statistical mechanics and information theory.”

🙂 🙂 🙂

Amazon India link:


Christiane Rousseau: AMS 2018 Bertrand Russell

Cheers to Prof. Christiane Rousseau and her team !

Math is fun: website

With thanks and regards to Colleen Young.

Household chores for mathematicians!!! :-)

Thanks to Evelyn Lamb and Scientific American. 🙂

The infinite hotel paradox : due Jeff Dekofsky

This hardcore stuff about “infinity” , quite nicely, explained was pointed out to me by my ISC XII student, Mr. Utkarsh Malhotra! 🙂


Permutations and Combinations: IITJEE Mains problem solving practice

Problem 1:

Find all natural numbers n such that n! ends with exactly 26 zeros.

Problem 2:

Find the largest two digit prime that divides 200 \choose 100.

Problem 3:

Find all natural numbers n \leq 14 such that n! + (n+1)!+(n+2)! is divisible by 25.

Problem 4:

When 30! is computed, it ends in 7 zeros. Find the digit that immediately precedes these zeros.

Problem 5:

Prove that \frac{(n^{2})!}{((n)!)^{n+1}} is a natural number for all n \in N.


Nalin Pihwa.