100
positive square numbers less than 50 are 7 these are : 1,4,9,16,25,36,49.These are less than 50.
6 and 28 are perfect numbers less than 50.
The prime numbers that are greater than 31 but less than 50 are: 37, 41, 43 and 47.
There are 15 prime numbers less than 50.
There are 15 prime numbers less than 50
100
positive square numbers less than 50 are 7 these are : 1,4,9,16,25,36,49.These are less than 50.
Square: 1, 4, 9, 16, 25, 36, 49. Triangular: 1, 3, 6, 10, 15, 21, 28, 36, 45.
Set of even numbers less than 50 and more than 40 = {42,44,46,48}
There are 15 composite numbers greater than 50 but less than 70
6 and 28 are perfect numbers less than 50.
The prime numbers that are greater than 31 but less than 50 are: 37, 41, 43 and 47.
There are 15 prime numbers less than 50.
It is the infinite set (-∞, 50)
14. Assuming dealing with only counting numbers (ie integers greater than 0): Numbers divisible by 5 or 7 are their multiples. 50 ÷ 5 = 10 → last multiple of 5 less than 50 is 9 x 5 → 9 numbers less than 50 are divisible by 5 50 ÷ 7 = 71/7 → last multiple of 7 less than 50 is 7 x 7 → 7 numbers less than 50 are divisible by 7 Numbers divisible by both are those which are multiples of their lowest common multiple = 35 50 ÷ 35 = 115/35 → last multiple of 35 less than 50 is 1 x 35 → 1 number less than 50 is divisible by both 5 and 7 and needs to be removed from both the above counts. → (9 - 1) + (7 - 1) = 14 numbers less than 50 are divisible by 5 or 7 but not both. If there is no restriction on numbers being greater than 0, there are infinitely many numbers as it includes the infinite number of negative numbers which are all less than 50 and provide an infinite number of numbers divisible by 5 or 7 but not both.
The prime numbers between 40 and 50 are 41, 43, and 47.