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.
