Hi, there. I'm happy to help with this.
Prompt:
To send a parcel, one is charged a fixed value of $3.95 plus $29.95 per item. How many items are there in the parcel?
This question is good for practicing estimation. The fixed value is close to $4, and the per item rate is close to $30.
Statement #1:
To send this parcel, one will spend between $260 and $315
9*30 = 270 ---> add 4 ---> $274 = approx price of nine parcels
10*30 = 300 ---> add 4 ---> $304 = approx price of ten parcels
Both are well within the range given, so the range given doesn't uniquely determine the number of parcels. Statement #1, by itself, is
insufficient.
Statement #2:
To send this parcel, one will spend between $300 and $330
$274 = approx price of nine parcels ---> is not in this range
$304 = approx price of ten parcels ---> is in this range
11*30 = 330 ---> add 4 ---> $334 = approx price of eleven parcels ---> is not in this range
The only possible number of parcels with a cost in this range is ten parcels. Statement #2, by itself, is
sufficient.
Answer =
B
Does this make sense? Let me know if you have any further questions.
Mike
