Question

f R = {x|x > 0} and S = {x| x < 3}, what is the number of integers in R S

Answer 1

SOLUTION

Given the question in the image, the following are the solution steps to answer the question.

STEP 1: Write the given data sets

$\begin{gathered} R=\mleft\lbrace x\mright|x>0\} \\ S=\mleft\lbrace x\mright|x<3\} \end{gathered}$

STEP 2: Write out the elements in both data sets

$\begin{gathered} R=\mleft\lbrace1,2,3,4,5,6,\ldots\infty\mright\rbrace \\ S=\mleft\lbrace-\infty,\ldots0,1,2\mright\rbrace \end{gathered}$

STEP 3: Write the elements common to both data sets

$\begin{gathered} R\Delta S=\mleft\lbrace1,2\mright\rbrace \\ nR\Delta S=2 \end{gathered}$

Hence, the number of integers in RS is 2