3. what is a counterexample for the conjecture?
conjecture: all balls are spheres.

a basketball
a football
a circle
a baseball

4. what is the conclusion of the following conditional?
a number is divisible by 3 if the sum of the digits of the number is divisible by 3.

the number is odd.
the sum of the digits of the number is divisible by 3.
if the sum of the digits of a number is divisible by 3, then the number is divisible by 3.
the number is divisible by 3.

5. another name for an if-then statement is a
conclusion
hypothesis
conditional
conjecture

6. every conditional has two parts. the part following if is the .
hypothesis
conclusion
inverse
converse

7. write this statement as a conditional in if-then form:
all triangles have three sides.

if a triangle has three sides, then all triangles have three sides.
if a figure has three sides, then it is not a triangle.
if a figure is a triangle, then all triangles have three sides.
if a figure is a triangle, then it has three sides.