Q: Is myocardial infarction a brain problem?
A: no
Explanation: Myocardial infarction is a problem in the heart. The equivalent in the brain would be similar to a stroke.

Q: Do you need different colored pens for sudoku?
A: no
Explanation: Sudoku is played both online and offline. Sudoku has no color component in the game.

Q: Did the Qwerty keyboard layout predate computers?
A: yes
Explanation: The Qwerty layout was originally developed for mechanical typewriters in the 1870s. ENIAC was considered to be the first computer, built in the late 1940s.

Q: Is week old chlorine water safe to drink?
A: yes
Explanation:
Chlorine is a chemical that is the second lightest halogen element. Chlorine is toxic and can attack the respiratory system of humans. Chlorine is highly soluble in water and will dissolve in around 4 and a half days. The Water Quality and Health Council states that chlorination of drinking water protects consumers from diseases caused by waterborne microorganisms.