Select all prime numbers from the list: 21, 29, 31, 49
Note
29 and 31 are prime (divisible only by 1 and itself). 21 = 3×7 and 49 = 7×7, so they are not prime.
Select all prime numbers from the list: 21, 29, 31, 49
29 and 31 are prime (divisible only by 1 and itself). 21 = 3×7 and 49 = 7×7, so they are not prime.