only 5 itself. Any other number ending in 5 is a multiple of 5 and so is not prime.
2 and 5
2 and 5.
the first 5 primes are 2,3,5,7,11
(105) = 3 * (35) = 5 * 7 (both primes, end)so, prime factors of 105 : 3,5,7(175) = 5 * (35) = 5 * 7 (both primes, end)so, prime factors of 175 : 5,5,7
(130) = 2 * (65) = 5 * 13 ( both primes, end of sequence)
there are 13 primes not 5.
theres more than 5 primes. but five primes are 2,3,5,7,11. amd theres also 23,29,31,37, and so on.
1450 as a product of primes = 2 * 5 * 5 * 29
There are only 2 primes in 80: 2 and 5.
20 as a product of primes = 2 * 2 * 5
break it into prime number multiples,10 = 2 * 5 (both prime numbers)example: factorize 387(387) = 9 * 43 (both primes , end of excercise)factorize 390:(390) = 2 * (195) = 3 * (65) = 5 * 13 (both primes , end of excercise)
Because the definition of twin primes is: two prime numbers with a difference of 2. 3 and 5 are both prime numbers, and their difference is 5 - 3 = 2 → they are twin primes.