Questions:(adsbygoogle = window.adsbygoogle || []).push({});

1) How many zeros are there at the end of 1994!

[where n ! stands for n factorial]

2) Prove that if x1, x2, ...., x100 are distinct natural odd numbers

1/x1 + 1/x2 + ........ + 1/x100 < 2

3) Prove that if 'p' is a prime number then coefficients of the terms of (1+x)^(p-1) are alternately greater and less by unity than some multiples of 'p'.

4) Prove that 2222^5555 + 5555^2222 is divisible by 7.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Number theory questions

**Physics Forums | Science Articles, Homework Help, Discussion**