41. RATTLE PRIMES LIKE RAMANUJAN? | |||
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They form an important part of '

It is said,

Ramanujan could rattle primes upto a crore

(1 00 00 000, 1 koti or 10 million).

If not so many like Ramanujan, it is good to know atleast a few primes.

Any one can easily work-out and remember primes below 100.

How many primes can you

a) 1 is not a prime (nor a

b) Evens are not primes (

c) Multiples of 5, like 15, 25, 35, ... are not primes.

d)

e) The first four primes 2, 3, 5, 7 are exceptions.

They do not follow any pattern.

We shall list the primes in 10 rows of 4 columns.

We shall test the

In fact, it is enough to test numbers upto 120 by 3 and 7.

You should work out the primes yourself and verify.

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 | ||||

Did you notice there are 25 primes below 100 and of these 15 are below 50?

If you are interested in rattling at least these 25 primes, then you may learn (

This takes

You may also work out more primes 'this way'.