What is the probability that a randomly chosen student has either blood group A or blood group B?

Answer: 50%

Step-by-step explanation:

imagine you had a pie and you cut it in half to discover their are two different flavors inside no more no less. by assuming theirs only two flavors how much would you say in percentage you would have ... it would be 50% because just like using quarters if you had 50 cents and 50 cents it would equal out to 100, in this case it would be percent you would say from the 2 groups that only 50 percent of the students would be likely to have that blood group