Question

If D is the set of whole numbers that are whole numbers less than 5, choose the selection below that correctly shows this set in roster and set­builder notation.

A. D = {0, 1, 2, 3, 4}; D = x 
B. D = {0, 1, 2, 3, 4, 5 , 6, 7, 8, 9, 10}; D = {x < 5}
C. D = {0, 1, 2, 3}; D =  x is a whole number, x < 5
D. D = {6, 7, 8, 9, 10}; D = {x < 5}

Answer 1

The answer is A. It specifies the whole numbers less than 5:

D = {0, 1, 2, 3, 4}

and then explains that x is a number such that it is whole and is less than 5.

Answer 2

A. D = {0, 1, 2, 3, 4}; D = x

Explanation:

In roster form we write the elements of a set separated by commas and enclose them in flower bracket {}.

While, in set builder form we write the properties of the elements of a set by using mathematical symbol and also enclosed them in {},

∵ Whole numbers are,

0, 1, 2, 3, 4, 5, 6, ...........

Thus, the whole numbers less than 5 are,

0, 1, 2, 3, 4

If D is the set of whole numbers less than 5,

Then roster form of D,

D = { 0, 1, 2, 3, 4 }

And, Set builder form of D,

D = x is a whole number, x < 5

Hence, OPTION A is correct.