41,43, and 47 are all prime numbers. so there are three prime numbers between 40 and 50
Apart from 2, all even numbers are composite. So the question is equivalent to all even numbers between 40 and 50. And these are ... ? 42, 44, 46 and 48.
I've found all the prime numbers...
31 and 37 are the only prime numbers between 30 and 40
The composite numbers between 30 and 40 are 32, 33, 34, 35, 36, 38, and 39.
1001,1111,1221,1331,1441,1551,1661,1771,1881,1991,2002,2112,2222,2332,2442,2552,2662,2772,2882,2992,3003,3113,3223,3333,3443,3553,3663,3773,3883,3993,4004,4114,4224,4334,4444,4554,4664,4774,4884,4994: 40 numbers in all.
41,43, and 47 are all prime numbers. so there are three prime numbers between 40 and 50
Apart from 2, all even numbers are composite. So the question is equivalent to all even numbers between 40 and 50. And these are ... ? 42, 44, 46 and 48.
I've found all the prime numbers...
31 and 37 are the only prime numbers between 30 and 40
There are 6 prime numbers between 14 and 40. They are: 17, 19, 23, 29, 31 and 37.
The composite numbers between 30 and 40 are 32, 33, 34, 35, 36, 38, and 39.
The prime numbers between 40 and 70 are 41, 43, 47, 53, 59, 61, and 67.
All of the numbers between 40 and 50 can be factors. The common factors of 40 and 50 are 1, 2, 5 and 10.
31 and 37
31, 37
68