# What are the odd numbers between 51 and 155?

The odd numbers between 51 and 155 are:

51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 75, 77, 79, 81, 83,
85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113,
115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139,
141, 143, 145, 147, 149, 151, 153, 155

### What odd composite number between 50 and 60 can be written as the sum of two prime numbers?

The odd composite numbers between 50 and 60 are 51, 55, and 57. Because all the primes are odd except for 2 and adding two odd numbers will result in an even number, one of the two prime numbers must be 2, which when added to an odd number will result in an odd number. So, we subtract 2 from each of these numbers and check whether it is prime. 51 - 2 = 49…

### The product of two odd prime numbers is 51 What are they?

the clue is that one of the factors must be <= square root(N). So, you know one number must be <=7 and there are only 4 possible primes that are eligible. They are 2,3,5 and 7. Because 51 is odd, we toss out 2. The number 5 only evenly divides into numbers ending in 0 or 5, so we can toss out 5. Then, the numbers are either 3*(51/3) or 7*(51/7). Only one of the…