Problem Task

Compound Inequalities

The Earth is Round and it spins once every 24 hours For the statement to be true is it okay if only one part is true or must they both be true? NOW lets look at a number compound statement and OR

First we’ll put both conditions on the number scale If the statement only work if both conditions are met we look for the x values that satisfy both conditions What are the x values that satisfy both conditions?

Solving Compound Problems AND

Jenny tells her mother she’ll take the bus home OR walk to her friend, Ji Soo’s house. Jenny ended up going to her friend, Ji Soo’s house. Has Jenny told the truth to her mother? In the previous section you looked at AND compound statements, also called CONJUNCTIONS Another type of compound statement is the OR statement, called a DISJUNCTION HERE is a language example of a DISJUNCTION How is DISJUNCTION different to a CONJUNCTION?

DISJUNCTIONS in MATH SOLUTION: UNION used for OR

DISJUNCTIONS in MATH SOLUTION: Any part of the line covered by an arrow

DISJUNCTIONS in MATH SOLUTION:

EXAMPLES

SOLUTION 17 sheep are shorn before Eric. One approach is to consider simpler cases and build a pattern. So, if the number of sheep before Eric is a multiple of 3, dividing by 3 gives the number shorn before Eric. If the number is not a multiple of 3, dividing the next multiple of 3 by 3 gives the number of sheep shorn. Fifty is not a multiple of 3. The next multiple of 3 after 50 is 51, and 51 ÷ 3 = 17, so 17 sheep are shorn before Eric.