200 elementary school students were surveyed to find their blood groups. Of those, 55 were of blood group A, 85 of blood group B, and 21 of blood group O.

What is the probability that a randomly chosen student has either blood group A or blood group B?
A)
0.25
B)
0.60
C)
0.70
D)
0.81

B?

3 answers

or C.
I like C, since there are 140/200 of the students with A or B blood.
Thank you :)