Answer:
The probability of blood group O is P(O) = 0.50
Step-by-step explanation:
P(A) Â = 35/100
P(B) Â = 10/100
P(AB) = 5/100
P(O) Â = ?
P(O) = 1 - ( P(A)+P(B) + P(AB))
    = 1 - (35/100 + 10/100 + 5/100)
    = 1 - 50/100
    P(O)  = 0.50