That set has no mode.
All of them except for 31 and 37 which are prime numbers
37
32, 9, 18, 51
All the numbers appear just once, so there is no mode.
That set has no mode.
13
It is 32 and the others are prime numbers
There are 4 prime numbers between 32 and 48: 37 41 43 47.
There is no mode, as all the numbers appear only once.
All of them except for 31 and 37 which are prime numbers
The only one is 37.
There is only one and it is 37
37
The mode for this particular set of number is 42. This is because there is two 42's in the set.
32, 9, 18, 51
All the numbers appear just once, so there is no mode.