Question

Which of the following is a prime number 67,65,63 or 60

Answer 1

Use the rule of divisibility :
60 is composite because it is even so it can be divided by 2
67 is prime because none if the divisiblility rules work on it
65 is composite because it has a 5 by the end which means it can be divided by 5
63 is composite because the sum of the digits equal to 9 which can be divided by 3 and 9