Question

1. Choose the correct solution in roster form.

S is the set of prime numbers that are less than 15.
A.{2,3,5,7,11,13}
B.{2,3,5,7,9,11,13}
C.{1,3,5,7,9,11,13}
D.{1,2,3,4,5,6,7,8,9,10,11,12,13,14,15}

Answer 1

A. {2,3,5,7,11,13}

Explanation:

Since, prime numbers are the whole numbers which have only two multiple which are 1 and itself.

Thus, the prime numbers are,

2, 3, 5, 7, 11, 13, 17, 19, 23, ..................

Note : 1 is not a prime number because it has only one multiple i.e. 1.

or it does not satisfy the definition of prime number.

Thus, the prime numbers that are less than 15,

2, 3, 5, 7, 11, 13

Which are the elements of the set S,

Hence, S = { 2, 3, 5, 7, 11, 13 }

OPTION A is correct.

Answer 2

S is the set of prime numbers that are less than 15. The correct solution in roster form is {1,3,5,7,9,11,13}. The answer is letter C. The rest of the choices do not answer the question above.