Question

Salim sells a machine at 20% profit on cost. His selling price is 10000 . Calculate cost price?

Answer 1

`therefore` `color(magenta)("The cost price is"` `color(magenta)($8333.34`

Explanation:

Let the cost price be `x`.

According to question,

`20% xxx+x=10000`

`20/100x+x=10000`

`1/5x+5/5x=10000`

`6/5x=10000`

`x=10000xx5/6`

`x=8333.34`

`therefore` `color(magenta)("The cost price is"` `color(magenta)($8333.34`

~Hope this helps! :)

Answer 2

Cost price is `8333.33`

Explanation:

This is an example of reverse percentage because we do not know the original value, but only the value AFTER an increase or decrease has taken place.

Percentage calculations can always be done using direct proportion.

`20%` was added on, so the amount we have represents `120%`

The cost price represents `100%`

`x/100 = 10000/120" "(larr "value")/(larr "percent")`

`x = (10000xx100)/120`

`x = 8333.33`