Question

Given set A = {1,2,3,4,...,4022}
If subset of A consists of k elements which satisfy there are 2 prime numbers each other, so the possible value of k is ....?
a. 2
b. 2012
c. 2013
d. 4022
e. 4023

Answer 1

"which satisfy there are 2 prime numbers each other" rewrite that please

Answer 2

least consists there are 2 prime numbers, maybe..

Answer 3

B is a subset of A with k elements and at least has 2 prime numbers in it

Answer 4

so u want the possible value of k

Answer 5

yeah, i think like that mukushla... thanks

Answer 6

2 prime numbers or 2 coprime numbers?

Answer 7

two prime numbers

Answer 8

i believe that jean is right...because none of the options are correct

Answer 9

i mean 2 coprime

Answer 10

why? give me ur reasons?

Answer 11

i mean options are not logical
if they mean 2 prime

B={4,6,8,...,4022,3,9,15,...4017} which its elements are more than 2012 and the trivial option to choose will be 4022

Answer 12

that example contradicts other options except 4022

Answer 13

Ok... how about u if B is a subset of A with k elements and always has 2 prime numbers in it?

Answer 14

u mean to find minimum value of k such that the statement is true ha?

B is a subset of A with k elements and always has 2 prime numbers in it...find the minimumvalue of k?

Answer 15

yes..

Answer 16

*minimum value

Answer 17

that will not be a nice problem because we just need to count prime numbers on the interval [1.4022] and nothing more than that

Answer 18

there are 556 primes less than 4022

Answer 19

so the minimum value of k will be 4022-556+2=3468

Answer 20

jean what is the answer for coprimes?

Answer 21

if i want to find the possible value of k, how?

Answer 22

possible values of k : \(3468\le k\le4022\)

Answer 23

so, the answer is 4022?

Answer 24

with that options yes 4022

Answer 25

but if B={2,3,4,6,8,10,12,14,16,...,4022}
n(B) = 2013?

Answer 26

is right to mukushla?

Answer 27

but if
B={9,15,4,6,8,10,12,14,16,...,4022}
n(B)=2013 and there is no prime in it

Answer 28

hehe.. lol
so, the best correct anwer is 4022
thank you...

Answer 29

@mukushla, is the best correct option is 4022?

Answer 30

sorry i was out yes more correct answer is 4022

Answer 31

ups... one more
how do u know there are 556 primes less than 4022?

Answer 32

lol
God of Wolfram told me
http://www.wolframalpha.com/input/?i=primes+less+than+4022

Answer 33

hahaha.. i think u have the special formula, not from wolfram :D

Answer 34

emm i think there is no formula for that ... just some approax formula

http://en.wikipedia.org/wiki/Prime_number_theorem

Answer 35

okok.. thanks, see u later.. by

Answer 36

see u.