Question

If the cost of 20 pens is Rs. 180, calculate the cost of 15 pens?

Answer 1

Given,

The cost of 20 pens is Rs. 180

To Find,

The cost of 15 pens =?

Solution,

We can solve the question as follows:

It is given to us that the cost of 20 pens is Rs. 180. We have to find the cost of 15 pens.

The cost of 20 pens = Rs. 180

If 20 pens cost Rs. 180, the cost of one pen will be 180 divided by 20.

The cost of one pen = $\frac{180}{20} = Rs.\: 9$

Now,

The cost of 15 pens will be equal to the cost of one pen multiplied by 15.

The cost of 15 pens = The cost of one pen x 15

                                 $= 9 * 15 = Rs.\: 135$

Hence, the cost of 15 pens is Rs. 135.