1 packet of biscuits costs Rs24 but a pack of 4 of the same packet of biscuits costs Rs84. What is effective discount (in%) on the price?

Options

A. 8
B. 10
C. 7.5
D. 12.5

Answer

To find the effective discount percentage on the price of the biscuits, we can follow these steps:

### Step 1: Calculate the cost of 4 packets of biscuits at the individual price.
- The cost of one packet of biscuits is Rs. 24.
- Therefore, the cost of 4 packets is calculated as:
\[ \text{Cost of 4 packets} = 4 \times 24 = 96 \text{ Rs.} \]

### Step 2: Determine the cost of the pack of 4 biscuits.
- The cost of the pack of 4 packets is given as Rs. 84.

### Step 3: Calculate the discount amount.
- To find the discount, subtract the cost of the pack from the cost of the individual packets:
\[ \text{Discount} = \text{Cost of 4 packets} - \text{Cost of pack of 4} = 96 - 84 = 12 \text{ Rs.} \]

### Step 4: Calculate the effective discount percentage.
- The effective discount percentage is calculated using the formula:
\[ \text{Discount Percentage} = \left( \frac{\text{Discount}}{\text{Cost of 4 packets}} \right) \times 100 \]
- Substituting the values:
\[ \text{Discount Percentage} = \left( \frac{12}{96} \right) \times 100 = 12.5\% \]

### Final Answer:
The effective discount on the price is **12.5%**.

---