Question

Ach one of the following conclusions has been made by children and adults. For which ones can you find a counterexample? (Select all that apply.)
A) If you triple any number and add 1, the resulting number is always an odd number.
B) If you double any number and add 1, the resulting number is always an odd number.
C) If a figure has four right angles, then it must be a rectangle.
D) If a number is divisible by 2 and by 3, then it is divisible by 6.
E) If you square a number, you get an even number.

Answer 1

A) Yes; counterexample: Tripling 3 and adding one results in the number 10

B) No counterexample possible

C) No counterexample possible

D) No counterexample possible

E) Yes; counterexample: Squaring 7 results in the number 49