A bag contains notes of Rs.10, Rs.20, and Rs.50 in the ratio of 1:3:5. If the total value of money in the bag is Rs.1920, find the number of Rs. 20 notes.

Options

A. 6
B. 30
C. 18
D. 12

Answer

To solve the problem step by step, follow these instructions:

### Step 1: Understand the Ratio
The notes of Rs.10, Rs.20, and Rs.50 are in the ratio of 1:3:5. This means for every 1 note of Rs.10, there are 3 notes of Rs.20 and 5 notes of Rs.50.

### Step 2: Assign Variables
Let:
- The number of Rs.10 notes = 1x
- The number of Rs.20 notes = 3x
- The number of Rs.50 notes = 5x

### Step 3: Calculate the Total Value
The total value of the notes can be calculated as follows:
- Value from Rs.10 notes = 10 * (1x) = 10x
- Value from Rs.20 notes = 20 * (3x) = 60x
- Value from Rs.50 notes = 50 * (5x) = 250x

Now, add these values together:
\[ \text{Total Value} = 10x + 60x + 250x = 320x \]

### Step 4: Set Up the Equation
According to the problem, the total value of money in the bag is Rs.1920. Therefore, we can set up the equation:
\[ 320x = 1920 \]

### Step 5: Solve for x
To find the value of x, divide both sides of the equation by 320:
\[ x = \frac{1920}{320} \]
Calculating this gives:
\[ x = 6 \]

### Step 6: Find the Number of Rs.20 Notes
Now that we have the value of x, we can find the number of Rs.20 notes:
\[ \text{Number of Rs.20 notes} = 3x = 3 \times 6 = 18 \]

### Final Answer
The number of Rs.20 notes is **18**.

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