A woman gives birth to a son. Two years later, she gives birth to another son. What is the probability that her third child will be a girl? Explain your reasoning.

50-50

Explanation:

No matter how many children a woman has had before, the probability of her child being a girl will always be 50%.

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.