Bunuel wrote:

Jim's Shirt Barn sells all shirts in stock via the Internet for $29.95 per shirt plus $3.95 per shipment. How many shirts were in the last order Jim's Shirt Barn shipped?

(1) The total price of the order was between 285 and 320 dollars.

(2) The total price of the order was between 300 and 335 dollars.

Lets say there were 'x' shirts in the last order. Thus total price of order = 29.95*x + 3.95. We need to find x (which has to be an integer).

(1) Given that 285 < 29.95*x + 3.95 < 320 . Taking 3.95 other side, we get:

285 - 3.95 < 29.95*x < 320 - 3.95 OR 281.05 < 29.95*x < 316.05

To make this easier, we can round off all numerical values to their nearest integers. Thus 281 < 30x < 316

Now dividing entire inequality by 30, we get:

9.66 < x < 10.5

Since x has to be an integer, the only possible value of x = 10. So

Sufficient.

(2) Given that 300 < 29.95*x + 3.95 < 335. Taking 3.95 other side, we get:

296.05 < 29.95*x < 331.05

Again rounding off to their nearest integers, we get: 296 < x < 331

Now dividing entire inequality by 30, we get:

9.8 < x < 11.03

x can take two integer values here, 10 and 11. So

not sufficient.

Hence

A answer