The Quick Ratio formula is:

$\text{Quick Ratio} = \dfrac{\text{Current Assets} - \text{Inventory} - \text{Prepaid Expenses}}{\text{Current Liabilities}}$

$2.0 = \dfrac{5{,}000 - 2{,}000 - 0}{\text{CL}} = \dfrac{3{,}000}{\text{CL}}$

$\text{CL} = \dfrac{3{,}000}{2.0} = \mathbf{Rs.\ 1{,}500}$

The quick ratio excludes inventory and prepaid expenses from current assets since these are less liquid. Dividing quick assets by the ratio gives current liabilities.

Let the price of the book $= p$. Total paid $= 1.04p$.

She paid $10 and received change less than $3.00, meaning total paid was more than $7.00:

$1.04p > 7.00 \Rightarrow p > 6.73$

She also received some change, so total paid $< \$10.00$:

$1.04p < 10.00 \Rightarrow p < 9.615$

So $6.73 < p < 9.615$. Now check each statement:

• Statement A: $p < \$9.50$ — Not necessarily, since $p$ can be up to $9.615$. ✗
• Statement B: $p > \$6.90$ — Not necessarily, $p$ can be $6.80$ (giving change $\approx \$2.93 < \$3.00$). ✗
• Statement C: Sales tax $= 0.04p < 0.04 \times 9.615 \approx \$0.385 < \$0.45$. This is always true within the valid range. ✓
• Statement D: Tax $> \$0.50$ would require $p > 12.50$, which is impossible here. ✗

Only Statement C must be true.

Normal price for 10 notebooks: $10 \times 59\text{¢} = 590\text{¢} = \$5.90$

Sale: 2 notebooks for 99¢, so 10 notebooks cost $5 \times 99\text{¢} = 495\text{¢} = \$4.95$

Savings $= \$5.90 - \$4.95 = \$0.95$

• \(n \geq 1\)
• \(0 \leq \ell \leq n-1\)
• \(-\ell \leq m \leq +\ell\)