Question

Match the following items. In a group of 100 persons, 85 had Rh positive blood (Rh factor present), 45 had Type O blood, and 38 had both type O and Rh positive blood. If one person had been selected at random from the group, what would the probability be: 1. that his blood type was Type O and Rh+? 1 19/50 2. that his blood type was not O? 4 7/100 3. that his blood type was Rh-? 5 3/20 4. that his blood type was Type O and Rh-? 3 11/20 5. that his blood type was Rh+? 2 17/20 6. that his blood type was not Type O or else was Rh+? 6 93/100

Answer 1

Part 1) that his blood type was Type O and Rh+?
we know that
38 out of 100 have type O and Rh+
so
the probability is 38/100,
which simplifies to 38/100------> divide by 2 both members----> 19/50

the answer part 1) is
19/50

part 2) that his blood type was not O?
we know that
45 out of 100 have type O
so
55 out of 100 don't have type O,
and the probability is ------> 55/100-----> divide by 5 both members----> 11/20

the answer part 2) is
11/20

Part 3) that his blood type was Rh-?
we know that
85 out of 100 have Rh+
so
15 out of 100 have Rh-,
so
the probability is 15/100------> divide by 5 both members----> 3/20

the answer part 3) is
3/20

Part 4)that his blood type was Type O and Rh-?
we know that
45/100 or 9/20 have type O
and
15/100 or 3/20 have Rh-,
so
multiply the fractions to get -----> (9/20)*(3/20)------> 27/400
which is about 7/100

the answer Part 4) is
7/100

Part 5) that his blood type was Rh+?
we know that
85/100 or 17/20 for Rh+

the answer part 5) is
17/20

Part 6) that his blood type was not Type O or else was Rh+?
we know that
O and Rh+ is 38/100,
non-O is 55/100,
and
add them to get 93/100

the answer part 6) is
93/100