5 and 7
It is not possible to multiply two prime numbers and get 90. You can add 43 and 47.
When you multiply two prime numbers together they become factors of the number that they equal. Since the number will have factors other than 1 and itself, the number cannot be prime.
There are no two prime numbers that multiply to 24. You need four numbers (even though one appears 3 times).
7 + 13 = 20 Note that there are no two prime numbers x and y that multiply to 20.
There are no such two prime numbers, as 167 is a prime number itself.
The two numbers you can multiply together to equal 782 are 23 by 34.
The two numbers you multiply together to equal 391 are 17 by 23.
No it can not
You will need to multiply six prime numbers to obtain 400: 400 = 5*5*2*2*2*2