A person purchased 10 shirts costing Rs 150 per shirt. Next day he again purchased the shirts costing Rs 150 per shirt at a discount of Rs 30 per shirt and that day he spent a toal of Rs 1800. What is the average cost per shirt (in Rs)?

Options

A. 125
B. 132
C. 138
D. 144

Answer

To find the average cost per shirt, we will follow these steps:

### Step 1: Calculate the cost of the first purchase
The person purchased 10 shirts at Rs. 150 each.

\[ \text{Cost of first purchase} = 10 \times 150 = 1500 \text{ Rs} \]

### Step 2: Determine the cost per shirt after the discount
The next day, the person purchased shirts at a price of Rs. 150 with a discount of Rs. 30 per shirt.

\[ \text{Discounted price per shirt} = 150 - 30 = 120 \text{ Rs} \]

### Step 3: Calculate the number of shirts purchased on the second day
The total amount spent on the second day is Rs. 1800. We can find the number of shirts purchased by dividing the total expenditure by the discounted price per shirt.

\[ \text{Number of shirts purchased on second day} = \frac{1800}{120} = 15 \text{ shirts} \]

### Step 4: Calculate the total number of shirts purchased
Now, we can find the total number of shirts purchased over both days.

\[ \text{Total shirts} = 10 + 15 = 25 \text{ shirts} \]

### Step 5: Calculate the total cost of all shirts
Now, we need to calculate the total cost of all shirts purchased.

\[ \text{Total cost} = \text{Cost of first purchase} + \text{Cost of second purchase} \]

The cost of the second purchase can be calculated as:

\[ \text{Cost of second purchase} = 15 \times 120 = 1800 \text{ Rs} \]

Thus,

\[ \text{Total cost} = 1500 + 1800 = 3300 \text{ Rs} \]

### Step 6: Calculate the average cost per shirt
Finally, we can find the average cost per shirt by dividing the total cost by the total number of shirts.

\[ \text{Average cost per shirt} = \frac{\text{Total cost}}{\text{Total shirts}} = \frac{3300}{25} = 132 \text{ Rs} \]

### Final Answer
The average cost per shirt is Rs. 132.

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