Question

21 and 61 which is composite and which is prime

Answer 1

21 is composite because of 1*21 or 3*7 and 61 is prime because nothing besides itself can be multiplied to get 61

Answer 2

21 is a composite, because 21 x 1 = 21, and 7 x 3 = 21

61 is a prime, because it can only be multiplied by 1 to get 61

hope this helps