20 May

## উচ্চমাধ্যমিক পরীক্ষার দিন ঘোষণা

উচ্চমাধ্যমিকের বাকি থাকা পরীক্ষাগুলোর দিন ঘোষণা করলেন শিক্ষামন্ত্রী পার্থ চট্টোপাধ্যায় ।
পরীক্ষাগুলো নেওয়া হবে জুন মাসের 29 এবং জুলাই এর 2 ও 6 । প্রত্যেক উচ্চমাধ্যমিক পরীক্ষাকেন্দ্রে 80 থেকে 100 জন  পরীক্ষার্থী পরীক্ষা দিতে পারবে ।

06 May

## Prime Numbers

### Definition of Prime Number

Prime number is a number which has only two factors 1 and the number itself
Examples: 2 = 1×2, 3=1×3,5=1×5,7=1×7,....
etc.
⊹ 1 is neither a prime nor a composite       number.
⊹ 2 is the smallest prime number.
⊹ Greatest two digits prime number is 97

### How many prime numbers from 1 to  100?

25 prime numbers from 1 to 100.

The prime numbers are
2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97

### How many prime numbers from 1 to 200?

46 prime numbers from 1 to 200

The prime numbers are
2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97,101,103,107,109,113,127,131,137,139,149,151,157,163,167,173,179,181,191,193,197,199

### Twin Primes Number

Two prime numbers whose difference is 2 are called twin primes.
For examples 3 and 5 are twin primes numbers since difference between 5 and 3 is 2.

### How many pairs of twin primes numbers from 1 to 100 ?

8 pairs of twin primes from 1 to 100

The pairs of twin primes numbers are
(3,5);(5,7);(11,13);(17,19);(29,31);(41,43);(59,61);(71,73)

03 May

02 May

18 April

27 February