Just 7. Any other number divisible by 7 isn't prime.
In any large range of numbers, more so the higher and larger the range is, there will be more composites than primes. It is far more likely that a given number will be divisible by some number less than the number itself, the higher you go.
Except for 1, all of them.
No. The 4 smallest primes are 2 3 5 7. Multiplying these gives 210. Note that 1 is not regarded as a prime no. If it were to be then no other number could be prime for all of them are divisible by 1.
No matter the conditions, you will not be able to find a number that is simultaneously more than 20 and less than 5.
number less than 100 that is divisible by 2 5 and 9 = 90
Divide it with primes less than half of the number.
Yes, 887 is a prime number. Recall that if a number is not prime then there exists a prime less than the square root of the number and this prime divides the number. So we need to check if the primes less than 30 divides 887 or not. These primes are 2,3,5,7,11,13,17,19,23,29.
Its square root is less than 9, but it is not evenly divisible by any number less than 9, other than 1, so it is a prime number