Math Is Fun Forum

mantastrike

Member

Registered: 2011-04-24

Posts: 64

PLEASE HELP me with this really hard QUESTION.

A study has been done to determine if three different drugs - A, B and C - help relieve headache paint. 60 subjects were given the drug and the following results records.

18 reported drug A worked.
24 reported drub B worked.
33 reported drug C worked.
7 reported both drug A and B worked.
15 reported both drug A and C worked.
21 reported both B and C worked.
36 reported that at least one of the drugs worked.

i. How many people felt none of the drugs worked?
ii. How many people found all three drugs worked?
iii. How many people found only Drug B worked?
iv. Draw a Venn diagram to represent the data.
v.State two more pieces of information you can now read from the Venn diagram.

PLEASE HELP ME WITH MY HOME WORK.
I would really appreciate if you can provide venn diagram.

THANK YOU ALL!

gAr

Member

Registered: 2011-01-09

Posts: 3,482

Re: PLEASE HELP me with this really hard QUESTION.

Hi,

i)  24
ii) 4
iii) 0
v) Only drug C worked for 1 person. Only drug A worked for nobody.

---

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

Bob

Administrator

Registered: 2010-06-20

Posts: 10,649

Re: PLEASE HELP me with this really hard QUESTION.

hi mantastrike

venn diagram below.

I started with the middle region = x

Then you can write the bit of A intersect B that does not overlap C as 7 - x

To get the bit of A that does not overlap B nor C do this

18 - (7-x) - x -(15-x) = x - 4  .... watch out for 'minus minus' here.

Once you have an algebraic expression for every region you can add them up, set them equal to 36, and solve for x.

(x-4) + (7-x) + ... + (x-3) = 36.

You should get gAr's answer for x.

Bob

Last edited by Bob (2011-05-03 06:13:28)

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

mantastrike

Member

Registered: 2011-04-24

Posts: 64

Re: PLEASE HELP me with this really hard QUESTION.

Hi,

i)  24
ii) 4
iii) 0
v) Only drug C worked for 1 person. Only drug A worked for nobody.

THANKS MATE!! can you please show me how you answered this?

mantastrike

Member

Registered: 2011-04-24

Posts: 64

Re: PLEASE HELP me with this really hard QUESTION.

hi mantastrike

venn diagram below.

I started with the middle region = x

Then you can write the bit of A intersect B that does not overlap C as 7 - x

To get the bit of A that does not overlap B nor C do this

18 - (7-x) - x -(15-x) = x - 4  .... watch out for 'minus minus' here.

Once you have an algebraic expression for every region you can add them up, set them equal to 36, and solve for x.

(x-4) + (7-x) + ... + (x-3) = 36.

You should get gAr's answer for x.

Bob

THANK YOU VERY MUCH!!

Bob

Administrator

Registered: 2010-06-20

Posts: 10,649

Re: PLEASE HELP me with this really hard QUESTION.

hi mantastrike

You're welcome

Bob

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

mantastrike

Member

Registered: 2011-04-24

Posts: 64

Re: PLEASE HELP me with this really hard QUESTION.

hi mantastrike

You're welcome

Bob

mate can u plz show how did gAr get thos answer? using U and ∩... I don't know which theorem to use. If you can tell me, I'll take it from there.
THANKS!!

gAr

Member

Registered: 2011-01-09

Posts: 3,482

Re: PLEASE HELP me with this really hard QUESTION.

Hi mantastrike,

These questions are pretty basic.
I thought you would put some effort and explain them here.

Bob already answered it.

First question can be answered without much work:
Number of subjects - Number of people who felt atleast one of the drugs worked
=60 - 36

---

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

mantastrike

Member

Registered: 2011-04-24

Posts: 64

Re: PLEASE HELP me with this really hard QUESTION.

Hi mantastrike,

These questions are pretty basic.
I thought you would put some effort and explain them here.

Bob already answered it.

First question can be answered without much work:
Number of subjects - Number of people who felt atleast one of the drugs worked
=60 - 36

you are VERY VERY VERY HELPFUL!! THANK YOU VERY MUCH!!

gAr

Member

Registered: 2011-01-09

Posts: 3,482

Re: PLEASE HELP me with this really hard QUESTION.

Hi mantastrike,

You're welcome.

---

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."