The numbers are co-prime so the only common factor is 1.
1 and 81 Those two numbers certainly divide into 81 though they are not the only numbers to do so.
81 Divide by three. 27,3 Divide by three. 9,3,3 Divide by three. 3,3,3,3 Stop.
3,
Yes.
The numbers are co-prime so the only common factor is 1.
The only prime numbers between 81 and 90 is... 83
83
1 and 81 Those two numbers certainly divide into 81 though they are not the only numbers to do so.
prime numbers that divide into 1155 = 3, 5, 7, 11
They are: 79+2 = 81
81 Divide by three. 27,3 Divide by three. 9,3,3 Divide by three. 3,3,3,3 Stop.
3,
There are only 9 numbers between 80 and 90 - so lets look at them all Remember we only need to find 1 number that will divide the number except for 1 and itself for it to be NON-PRIME. 81 - 3 will of course divide this number - so not prime. 82 - 2 will of course divide this number - so not prime. 83 - PRIME!!! 84 - 3 will of course divide this number - so not prime. 85 - 5 will of course divide this number - so not prime. 86 - 2 will of course divide this number - so not prime. 87 - 3 will of course divide this number - so not prime. 88 - 2 will of course divide this number - so not prime. 89 - PRIME!!! So, the only numbers between 80 and 90 that are primes are 83 and 89!
Yes.
57 is divisible by the prime numbers of 3 and 19
Yes, these numbers: 1, 3, 9, 27, 81.