140
140
140
You can, in which case it is 140.
100
100. (The digit following the hundreds digit is 3 which is less than 5, so 138 rounds down to 100.)
138 is already a whole number in simplest form.
It is 140
150
Round it up - to 140.
140
138 is not prime. 138 = 2 * 3 * 23