Chapter P, Prerequisites - Section P.2 - Real Numbers - P.2 Exercises - Page 16: 44

(a) A $\cup$ B $\cup$ C={1,2,3,4,5,6,7,8,9,10} (b) A $\cap$ B $\cap$ C={$\emptyset$}

A union of sets includes all of the numbers in all of the sets. An intersection of sections includes any common numbers included in all sets. (a) A $\cup$ B $\cup$ C={1,2,3,4,5,6,7,8,9,10} (b) A $\cap$ B $\cap$ C={$\emptyset$}