Problema Solution

10. A survey of fruit tree growers showed the following:

59 grew raspberries 23 grew both raspberries and blueberries

50 grew blueberries 11 grew both raspberries and strawberries

27 grew strawberries 14 grew both blueberries and strawberries

9 grew all three types 13 grew none of these three

Create a Venn diagram to reflect the above data, label your diagram clearly and submit to the Dropbox. Use your diagram to answer the following questions here.

(a) How many grew only blueberries?

(b) How many grew both raspberries and blueberries, but not strawberries?

(c) How many grew only raspberries?

(d) How many grew none of these three or only strawberries?

(e) How many fruit tree growers were surveyed?

(Points : 7)

Answer provided by our tutors

There are 8 types of growers here.

Grower       Growing       Growing          Growing 

type       Raspberries   Blueberries      Strawberries

Type #1         YES           NO           NO

Type #2         YES          YES           NO

Type #3          NO          YES           NO 

Type #4         YES           NO          YES

Type #5         YES          YES          YES

Type #6          NO          YES          YES

Type #7          NO           NO          YES

Type #8          NO           NO           NO

Let's draw three mutually overlapping circles:

Notice that there are 8 regions.

Regions #1, #2, #4, and #5 make up the set R, of raspberry growers.

       

       Region #1 consists only of those growing raspberries, but who are

       NOT growing blueberries and NOT growing strawberries.

       Region #2 consists only of those growing BOTH raspberries and

       blueberries, but who are NOT growing strawberries.

      

       Region #3 consists only of those growing blueberries, but who are

       NOT growing raspberries and NOT growing strawberries.

       Region #4 consists only of those growing BOTH raspberries and

       strawberries, but who are NOT growing blueberries.

       Region #5 consists only of those growing ALL THREE kinds of berries. 

      

       Region #6 consists only of those growing BOTH blueberries and

       strawberries, but who are NOT growing raspberries.

       Region #7 consists only of those growing strawberries, but who are

       NOT growing raspberries and NOT growing blueberries.

       Region #8 consists only of those NOT growing ANY of the 

       kinds of berries.

Let's start with the most inclusive, i.e., those that grew some

of all three types of berries:

>>...9 grew all three types...<<

That's the growers of type #5, so we erase #5 and put 9 in its place:


>>...23 grew both raspberries and blueberries...<<

Regions #2 and #5 grew raspberries and blueberries, and since region #5

has 9 of the 23 already accounted for, the other 23-9 or 14 growers are in

region #2, so erase #2 and put 14 in its place

          

>>...11 grew both raspberries and strawberries...<<

Regions #4 and #5 grew raspberries and strawberries, and since region #5

has 9 of the 11 already accounted for, the other 11-9 or 2 growers are in

region #4, so erase #4 and put 2 in its place


>>...14 grew both blueberries and strawberries...<<

Regions #5 and #6 grew blueberries and strawberries, and since region #5

has 9 of the 14 already accounted for, the other 14-9 or 5 growers are in

region #6, so erase #6 and put 5 in its place


>>...59 grew raspberries...<<

Regions #1, #2, #5, and #4 grew raspberries, and regions #2, #5, and #4

have respectively 14, 9 and 2 of the 59 already accounted for, so we

add 14+9+2 and get 25 of the 59 already accouted for, that leaves

59-25 or 34 in region #1, so erase #1 and put 34 in its place

>>...50 grew blueberries...<<

Regions #2, #3, #5, and #6 grew raspberries, and regions #2, #5, and #6

have respectively 14, 9 and 5 of the 50 already accounted for, so we

add 14+9+5 and get 28 of the 50 already accouted for, that leaves

50-28 or 22 in region #3, so erase #3 and put 22 in its place

>>...27 grew strawberries...<<

Regions #4, #5, #6, and #7 grew strawberries, and regions #4, #5, and #6

have respectively 2, 9 and 5 of the 27 already accounted for, so we

add 2+9+5 and get 16 of the 27 already accouted for, that leaves

27-16 or 11 in region #7, so erase #7 and put 11 in its place

>>...13 grew none of these three...<<

These 13 are all in region #8, so erase #8 and put 13 in its place

(a)   How many grew only blueberries?

These are in region #3, so the answer is 22

(b)   How many grew both raspberries and blueberries, but not strawberries?

These are in regions #2 and #5, so the answer is 14+9 or 23

(c)   How many grew only raspberries?

These are in region #1, so the answer is 34

(d)   How many grew none of these three or only strawberries?

These are in regions #8 and #1, do the answer is 13+34 or 47.

(e)   How many fruit tree growers were surveyed?

We add the numbers is all the eight regions:

34 + 14 + 22 + 2 + 9 + 5 + 11 + 13 = 110.