Answer:
Total number of donors:
Total donors
=
1200
Total donors=1200
Blood types:
Type O: 570 donors
Type A: 440 donors
Type B: 12 donors
Type AB: unknown (let's denote it as
x)
Finding the number of AB donors:
The total number of donors should be equal to the sum of donors of all blood types:
570
(
O
)
+
440
(
A
)
+
12
(
B
)
+
(
AB
)
=
1200
570(O)+440(A)+12(B)+x(AB)=1200
So, we can solve for
x:
570
+
440
+
12
+
=
1200
570+440+12+x=1200
1022
+
=
1200
1022+x=1200
=
1200
−
1022
x=1200−1022
=
178
x=178
Thus, the number of donors with type AB blood is 178.
Probability that a randomly selected donor is type O:
(
Type O
)
=
Number of type O donors
Total number of donors
=
570
1200
=
19
40
≈
0.475
P(Type O)=
Total number of donors
Number of type O donors
=
1200
570
=
40
19
≈0.475
Probability that a randomly chosen donor may donate to a recipient with type A blood:
A recipient with type A blood can receive blood from donors with type A or type O blood.
So, the total number of donors that can donate to a type A recipient is:
Number of type A donors
+
Number of type O donors
=
440
+
570
=
1010
Number of type A donors+Number of type O donors=440+570=1010
Therefore, the probability is:
(
Donor for Type A recipient
)
=
1010
1200
=
101
120
≈
0.8417
P(Donor for Type A recipient)=
1200
1010
=
120
101
≈0.8417
Summary:
The number of donors with type AB blood is 178.
The probability that a randomly selected donor is type O is 0.475.
The probability that a randomly chosen blood donor may donate to a recipient with type A blood is approximately 0.8417.