Question

After a mark-up of `40%` was added to an item a boy sells it for `Rs.35`. What was his cost price and how much was his mark-up?

Answer 1

The cost price is Rs.25 and the markup is Rs.10.

Explanation:

The important thing to note here is that you cannot just find 40% of Rs.35 and subtract it.

The boy's cost price represents 100%, onto which 40% is added to give Rs.35.

Therefore Rs.35 represents `140%` of the cost price and we need to find the value of the 100% and the 40%.

Using
direct proportion:

`35/140 = x/100`

`x = (35xx100)/140`

`x = 25" "larr` this is the cost price.

`35-25 = 10" "larr` this is the mark up

Make an equation Let the cost price be `p`

`140% xx p = 35`

`140/100 xx p= 35`

`p = 35 xx 100/140`

`p = 25`