How much ( in % ) should the cost be increased by to get the intended profit figure.
I just picked numbers and it seems so much easier.
Let 100$ be the sales price
You want to be left with a profit of 10$
The problem also states that expenses are 15% of sales price = 15$
Therefore, the rest, 100$ - 10$ - 15$ = 75$ which must be the cost of the product.
To find the markup, --> 25$ / 75$ = 33.3%