Directions: Study the table and answer the question that follows.

The table gives the total number of notebooks sold by five stationery counters on a particular day, along with the ratio of hardcover notebooks to softcover notebooks sold by each counter.

Stationery Counters	Total Notebooks Sold	Hardcover Notebooks : Softcover Notebooks
A	135	5:4
B	140	9:5
C	180	4:5
D	160	13:19
E	150	7:8

If Counter B sold only 30% of its available hardcover notebooks, while Counter A had 75% of its hardcover notebooks left unsold, Counter A's total available hardcover notebooks were what percentage of Counter B's total available hardcover notebooks?

The correct option is 100%.

To find the percentage of Counter A's total available hardcover notebooks relative to Counter B's total available hardcover notebooks, we can break down the problem into step-by-step calculations using the data given in the table.

Step 1: Calculate the number of hardcover notebooks sold by Counter A and Counter B

From the table, for Counter A:

Total notebooks sold = 135

Ratio of Hardcover notebooks to Softcover notebooks sold = 5 : 4

Total ratio parts = 5 + 4 = 9 parts

Number of hardcover notebooks sold by Counter A:

$\text{Hardcover sold by A}=\frac{5}{9}\times 135=75$

From the table, for Counter B:

Total notebooks sold = 140

Ratio of Hardcover notebooks to Softcover notebooks sold = 9 : 5

Total ratio parts = 9 + 5 = 14 parts

Number of hardcover notebooks sold by Counter B:

$\text{Hardcover sold by B}=\frac{9}{14}\times 140=90$

Step 2: Calculate the total available hardcover notebooks at Counter A

Counter A had 75% of its hardcover notebooks left unsold, which means the percentage of hardcover notebooks sold by Counter A is:

$100\%-75\%=25\%$

So, 25% of Counter A's total available hardcover notebooks equaled 75 notebooks.

Total available hardcover notebooks for Counter A:

$\text{Total available (A)}=\frac{75}{25}\times 100=300$

Step 3: Calculate the total available hardcover notebooks at Counter B

Counter B sold only 30% of its available hardcover notebooks, which equals 90 notebooks.

Total available hardcover notebooks for Counter B:

$\text{Total available (B)}=\frac{90}{30}\times 100=300$

Step 4: Find the required percentage

We calculate what percentage Counter A's total available hardcover notebooks are of Counter B's total available hardcover notebooks:

$\text{Percentage}=\left(\frac{\text{Total available (A)}}{\text{Total available (B)}}\right)\times 100\%$

$\text{Percentage}=\left(\frac{300}{300}\right)\times 100\%=100\%$

Hence, Counter A's total available hardcover notebooks were 100% of Counter B's total available hardcover notebooks.