If the cost of 20 pens is Rs 110, what is the cost of 4 pens ?

Options

A. Rs 24
B. Rs 22
C. Rs 32
D. Rs 42

Answer

To find the cost of 4 pens when the cost of 20 pens is Rs 110, we can follow these steps:

### Step 1: Find the cost of 1 pen.
To find the cost of 1 pen, we divide the total cost of 20 pens by the number of pens.

\[ \text{Cost of 1 pen} = \frac{\text{Total cost of 20 pens}}{\text{Number of pens}} = \frac{110}{20} \]

### Step 2: Simplify the fraction.
Now, we simplify the fraction:

\[ \frac{110}{20} = \frac{11}{2} \quad \text{(by dividing both the numerator and denominator by 10)} \]

### Step 3: Calculate the cost of 4 pens.
Now that we have the cost of 1 pen, we can find the cost of 4 pens by multiplying the cost of 1 pen by 4.

\[ \text{Cost of 4 pens} = \text{Cost of 1 pen} \times 4 = \frac{11}{2} \times 4 \]

### Step 4: Perform the multiplication.
Now, we perform the multiplication:

\[ \frac{11}{2} \times 4 = \frac{11 \times 4}{2} = \frac{44}{2} = 22 \]

### Final Answer:
The cost of 4 pens is Rs 22.

---