What is the ratio of the price of a pencil to that of a ball pen if pencils cost ₹ 96 per score and ball pens cost ₹ 50.40 per dozen?

Given, pencils cost ₹ 96 per score and ball pens cost ₹ 50.40 per dozen.

We know, 1 score = 20

1 dozen = 12

By using the unitary method,

$\text{Cost of 1 item = }\frac{\text{cost of all item}}{\text{number of items}}$

Then, 

The price of 1 pencil = $\frac{96}{20}= \mathbf{₹}\mathbf{ }\mathbf{4}\mathbf{.}\mathbf{8}$

The price of 1 ball pen = $\frac{50.40}{12}= \mathbf{₹}\mathbf{ }\mathbf{4}\mathbf{.}\mathbf{2}$

Now, the required ratio:

$\Rightarrow \frac{\mathrm{Price} \mathrm{of} 1 \mathrm{pencil}}{\mathrm{Price} \mathrm{of} 1 \mathrm{ball} \mathrm{pen}} = \frac{4.8}{4.2}$

 $\Rightarrow \frac{\mathrm{Price} \mathrm{of} 1 \mathrm{pencil}}{\mathrm{Price} \mathrm{of} 1 \mathrm{ball} \mathrm{pen}} = \frac{\mathbf{8}}{\mathbf{7}}$

Therefore, the ratio of the price of a pencil to that of a ball pen is 8: 7.