Number between 1 to 301 Find the non prime numbers is not divisible by 2 3 5 7

(11,13,17,19,23)
(23*11)=253 noprime
(23*13)=299 noprime
(19*11)=209 noprime
(19*13)=247 noprime
(17*11)=187 noprime
(17*13)=221 noprime
(17*17)=289 noprime
(11*13)=143 noprime
(13*13)=169 noprime
(11*11)=121noprime
ans 10
8 years agoHelpfull: Yes(3) No(0)
My approach:

Multiplication of prime with itself or other primes gives composite numbers. So

11*11=121

11*13=143

11*17=187

11*19=209

11*23=253

11*29=319 which is not in range of 1-301 so we cant conider it

13*13=169

13*17=221

13*19=247

13*23=299

17*17=289

17*19=323 which is not in range of 1-301 so we can't consider it..so 10 would be my answer .
8 years agoHelpfull: Yes(2) No(1)
299
non prime can be divided by only 13
8 years agoHelpfull: Yes(1) No(1)
non prime no. which are not divisible by 2,3,5,7 can not be divisible by 4,6,8,9 also.

So only the Product of prime no.s which are less than 301 will be the answer.

so range of prime no.s are (11,13,17,19,23)
11*(any of the 5 prime No.)
8 years agoHelpfull: Yes(0) No(1)
121,143,299 are some of the numbers
8 years agoHelpfull: Yes(0) No(1)
answer is 79
refer solved example 1.33 of ARUN SHARMA QUANT of chapter number systems..
8 years agoHelpfull: Yes(0) No(1)
Answer will be 69.
8 years agoHelpfull: Yes(0) No(0)
(11,13,17,19,23) = 5C3 =10
8 years agoHelpfull: Yes(0) No(0)
7
11*13,11*17,11*19,11*23
13*17,13*19,13*23
8 years agoHelpfull: Yes(0) No(0)

Number between 1 to 301. Find the non prime numbers is not divisible by 2,3,5,7.