..Sales question..

ryan_kidz

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A newspapaer advertises that it sells the Sunday paper for one-third the price of the rest of the week's papers. If a weekly subsription costs between $2.20 and $2.30, what is the cost of one of one sunday paper and one daily paper?

and also, any body can explain to me what does it means by "costs between $2.20 and $2.30"? i don't really get it.

thnx!
 
ryan_kidz said:
A newspapaer advertises that it sells the Sunday paper for one-third the price of the rest of the week's papers. If a weekly subsription costs between $2.20 and $2.30, what is the cost of one of one sunday paper and one daily paper?

and also, any body can explain to me what does it means by "costs between $2.20 and $2.30"? i don't really get it.

thnx!
The "between" thing is a bit odd, but not all that unusual. To me, that might mean we may have trouble finding a unique solution. we may find a couple of solutions and we'll have to pick the one in the specifiec Domain.

We have a strike against us with this problem statement. I cannot tell what this means, "the price of the rest of the week's papers". It may mean any ONE of the daily papers' costs or it could mean all six (6) combined. This may be the answe to the previou paragraph. Let's work it both ways and see if only one gives the right solution.

X = Cost of Daily
Y = Cost of Sunday

Assume: It means just one daily, then Y = X/3 and 3*Y = X

Then 2.20 < Y + 6X < 2.30
Then 2.20 < (X/3) + 6X < 2.30
Then 2.20 < 19*(X/3) < 2.30
Then 6.60 < 19*X < 6.90
Then 0.3474 < X < 0.3632 ==> 0.35, 0.36 are the only choices.
Then 0.1158 < Y < 0.1211 ==> 0.12 is the only choice. This means that 0.36 = X

Y + 6*X = 0.12 + 6*0.36 = 2.28

Assume: It means the total of all six (6) dailies, then Y = (6*X)/3 = 2*X

Then 2.20 < Y + 6X < 2.30
Then 2.20 < 2X + 6X < 2.30
Then 2.20 < 8X < 2.30
Then 0.275 < X < 0.288 ==> 0.28 is the only choice.
Then Y = 2*0.28 = 0.56

Y + 6*X = 0.56 + 6*0.28 = 2.24

That's a little disappointing. We still have two possible answers. Maybe we should have worked in the cost of the Carrier's tip?

Note: This really is not really so ambiguous, but only because of one thing that may not be obvious. In the U.S., it is traditional for the Sunday paper to be the biggest and most expensive. The cost of the Sunday paper is ALWAYS greater than the cost of the dailies. This eliminates one of the solutions and pins it down to a unique solution.
 
thnx alot for the answer tkhunny!

i really appreciate it, but i'm still kinda confused ^-^
 
Use this simple logic

Let Sunday newspaper = x
Weekday price = 3x

Total weekly cost = x + 6[3x] = 19x

19x equals something between 220 cents and 230 cents
The catch here is that the weekly bill has to be a whole number. It can be 222 cents or 224 cents or whatever, but it can't be 223.5 cents or something like this.

For x to be a whole number, the total weekly bill should be divisible by 19.
Because 19x = 220 ~ 230

We have to find a number between 220 and 230 divisible by 19.

There is only one number 228.

Total weekly bill is 228 cents
Sunday price is 228/19 = 12 cents
Weekday price is 12*3 = 36 cents

Got it???
 
Well, whadda ****: since range = 220 to 230:
(219 + x) / 19 = k where k = any positive integer

x = 19k - 219

k= ceiling(219 / 19) = 12

x = 228 - 219 = 9

219 + 9 = 228
 
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