Question

PLEASE HELP!!!!!!!!!!!!!!!!!!!!!!!!!!! IT's about ALIENS :)

Stephen wants to learn to communicate with the aliens so he spends lots of time with them. For a week he spends at least some time with then everyday. The number of days he spends time with them after noon is one more than the number he spends time with them before noon. The number of days he spends time with them only before noon is half as many as the number he spends time with them only after noon.

How many days does he spend time with the aliens both before and after noon?

PLEASE USE A VENN DIAGRAM TO SHOW WORK DONE. THX!

Answer 1

What does this have to do with math?

Answer 2

Ohhhh ok nevermind

Here is the definition of a venn diagram:
A Venn diagram is a diagram that uses circles to illustrate the relationships among sets.

Example:
The Venn diagram below shows the number of grade 5 students who scored above 50% on Math, above 50% on Science, and above 50% on both Math and Science.

From the Venn diagram, we learn that 16 students scored above 50% on Math, 21 students scored above 50% on Science, and 6 students scored above 50% on both Math and Science.

Answer 3

thanks, what a venn diagram is
i just need to know how you solve this problem

Answer 4

Are you there? I think I have the pieces we just need to put them together

Answer 5

yes i'm here

Answer 6

I am missing a number somewhere. I need to reread the question. there is only a total of 7 days!!

Answer 7

a = b + 1
(a-c)/2 = (b-c)
7 = a + b - c
These are our three equations

Answer 8

? uhm i'm sorry i stll don't really get it... perhaps explain like what it's taking about cuz like i don't get the one more than the number stuff in the problem...

Answer 9

Let a = total aliens after noon
Let b = total aliens before noon
Let c = # of aliens in both

(a-c) is only after noon
(b-c) is only before noon

From the problem we have 2 equations we can write.

a = b + 1
(a-c)/2 = (b-c)

We have 2 equations and 3 unknowns so we still can't solve. We need another equation, a total equation.

7 = a + b - c

Answer 10

a = b + 1
(a-c)/2 = (b-c) -> b = (a-c)/2 + c
7 = a + b - c

Solve by substitution.
7 = ( b + 1) + b - c
7 = 2b + 1 - c
7 = 2[(a-c)/2 + c] - c
7 = a - c + 2c - c
a = 7
b = 6
c = 6

That's a strange answer. I'm going to recheck my equations.

Answer 11

I don't see a mistake.
a = 7 days after noon
b = 6 days before noon
c = 6 days both

Answer 12

Now I'll answer your questions

Answer 13

? uhm i'm sorry i stll don't really get it... perhaps explain like what it's taking about cuz like i don't get the one more than the number stuff in the problem...

Answer 14

@hartnn can you double check this. My answer seems unlikely although I think my math is sound

Answer 15

Okay we'll break down the wording first

Answer 16

Let a = number after noon
Let b = number before noon

It is saying that he spends one more day with them after noon than before noon.

Say b is 10. a would have to be 11 right?

So we can write this equation

b + 1 = a

Plugging in our example to see if it works we get

10 + 1 = 11
11=11 check

Answer 17

Do you understand that?

Answer 18

sort of?

Answer 19

What specifically confuses you about that explanation?

Answer 20

the equation part

Answer 21

We want something that represents what is happening. We use variables because we don't know what they are at first.

Answer 22

If I told you I was 2 years older than you what equation would you write?

Answer 23

your age + 2 = my age

Answer 24

Is this helping?

Answer 25

a little sorry my best subject isn't math

Answer 26

oh like if my granpa was twice my age and i was like... 64 that would be 64 X 2 right?

Answer 27

really bad example because grandpas are usually not that age compared to real life

Answer 28

ya thats correct