Question

A bottle of 250 vitamin tablets sells for $3.75. At this rate, what should a bottle of 40 tablets cost? (Choose the answer, marked correctly, from the standard grids.)

Answer 1

I under the equation looks like this:
\[\frac{ 3.75 }{ 250 } = \frac{ x }{ 40 }\]
But why is 3.75 over 250?

Answer 2

Cross multiply (3.75 * 40)
250x= 150; Divide by both sides

Answer 3

I know how to solve it. I know how to do problems like this. I just never understood why I am putting 250 in the denominator.

Answer 4

Umm, change it around?

Answer 5

oh you did it correctly

Answer 6

I know I did it correctly... why is 250 in the denominator...

Answer 7

let me set another example so that it will be easier

Answer 8

it's like saying a pan of pizza with eight slices cost 8 bucks
if I were to buy only a slice then we both know intuitively that it'd be a dollar

Answer 9

that is
8slices/8bucks = 1slice/1buck

Answer 10

let us try another one

Answer 11

"A bottle of 250 vitamin tablets sells for $3.75" By putting \(\ \dfrac{$3.75}{250}\) you're finding how much each tablet is worth.

Answer 12

I suspect troll, but flutter it

Answer 13

Yes... I am aware of how to solve it. I know how to solve these proportions intuitively. That's the problem. I'm asking for insight.

Answer 14

I am giving the insight

Answer 15

don't listen to fiz

Answer 16

I appreciate it, Nincompoop.

So, we put costs on the top?

Answer 17

LOL

Answer 18

xD What.. I explained the reasoning behind putting 3.75/250, not how to solve it..

Answer 19

Hmm. It kind of wouldn't make sense if we divided 3.75 into 250. Because that would mean each pill would be like 60 dollars.

Answer 20

it depends on what you are looking for, comp
you put on the numerator that is which you wanted to break into parts, and the number of parts you want to break it into will be the denominator

Answer 21

http://prntscr.com/4t5bhr

Answer 22

Melissa went shopping and spent half of her money on shoes, a third on a blouse, a tenth to take her boyfriend to lunch, and she came home with $12. How much did she start out with?

So, let me see.

x = x/2 + x/3 + x/10 + 12

And we would find the LCM

30 = 15x + 10x + 3x + 360

Now we add like terms, and solve?

Answer 23

I want to break a pan of pizza into 8 parts
will be interpreted as \( \frac{1pan pizza}{8 slices}\)

Answer 24

Ah, alright. I get it. I'm just trying to refresh my memory on the basics and stop. Thanks a lot, @nincompoop

Answer 25

in your problem, you want to break the total cost into 250 parts to get the cost of each pill

Answer 26

It's been years since I touched on algebra and arithmetic. :=P

Answer 27

I understand it Nin. I appreciate your help a lot :)

Answer 28

If you gave me trig, I could do that easily. I just need to refresh my memory on the basics. Felt I've been neglecting it lately. xc

Answer 29

it's cool
in chemistry, you will be making good use of fraction and conversion by dimensional analysis

Answer 30

I made a 93 in chemistry. I don't know how, to be honest. A lot of the stuff is just repetitive for me. It's become just another process when I read something and analyze it. I like to go over these concrete notions I have and try to understand them more.

Answer 31

@Compassionate I don't know if anyone already said this, but there is no matter in where you put the 250 and the price, so long as you put everything else they same way.

Answer 32

the same way**

Answer 33

i have a suggestion

Answer 34

forget about the ratio for a second
compute the price per tablet
if 250 cost \(\$3.75\) then each one costs \(\frac{3.75}{250}\)

Answer 35

that is the cost of one tablet, then 40 tablets cost 40 times as much,
\[\frac{40\times 3.75}{250}\]

Answer 36

and 60 would cost 60 times as much etc

Answer 37

Shouldn't 40 tablets cost 40 times less? Since we have 250 tablets for 3.75 a piece...

Answer 38

oh no it is not 250 for $3.75 each!

Answer 39

it is $3.75 for the whole lot of 250

Answer 40

Oh, righto right! Hehe! Okay, so I understand now how we can have 250 divided into 3.75 to get the price per-tablet.

But what did you do when you multiplied 3.75 by 40 then divided it all by 250?

Answer 41

If you multiply it by 40, wouldn't that just raise the cost of each tablet?

Answer 42

\[3.75\div 250\] is the "unit price" i.e. the price per tablet

Answer 43

you want to know how much whatever number of tablets cost, you multiply it by that number