If 18 dolls cost Rs630, how many dolls can be bought for Rs 455?

Answer

To solve the problem of how many dolls can be bought for Rs 455 when 18 dolls cost Rs 630, we can follow these steps:

### Step 1: Understand the relationship
We know that the number of dolls and the cost are directly proportional. This means that if the cost decreases, the number of dolls we can buy will also decrease.

### Step 2: Set up the proportion
We can set up the proportion based on the given information:
\[ \frac{\text{Number of dolls}}{\text{Cost}} = \frac{18 \text{ dolls}}{630 \text{ Rs}} \]
Let \( x \) be the number of dolls we can buy for Rs 455. Then we can write:
\[ \frac{x \text{ dolls}}{455 \text{ Rs}} = \frac{18 \text{ dolls}}{630 \text{ Rs}} \]

### Step 3: Cross-multiply to solve for \( x \)
Cross-multiplying gives us:
\[ x \cdot 630 = 18 \cdot 455 \]

### Step 4: Calculate \( 18 \cdot 455 \)
Now, we calculate \( 18 \cdot 455 \):
\[ 18 \cdot 455 = 8190 \]

### Step 5: Divide by 630 to find \( x \)
Now we can find \( x \) by dividing both sides by 630:
\[ x = \frac{8190}{630} \]

### Step 6: Simplify the fraction
Now, we simplify \( \frac{8190}{630} \):
\[ x = 13 \]

### Conclusion
Thus, you can buy **13 dolls** for Rs 455.

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