Help, sure this should be easy!

[rmorgan88]

I have a maths issue that I’m sure should be easy but I can’t get my head round it.
If I sell something for £100 and the shop takes an 18% cut. What % do I need to add to that £100 to ensure that once the cut is taken, I still end up with £100. What’s the formula for calculating this?

Thank you, feeling dumb!

 

[Deleted member 4993]

I have a maths issue that I’m sure should be easy but I can’t get my head round it.
If I sell something for £100 and the shop takes an 18% cut. What % do I need to add to that £100 to ensure that once the cut is taken, I still end up with £100. What’s the formula for calculating this? Thank you, feeling dumb!

use the concept:

selling price = (expected net revenue) + (shop-cut)​

Please show us what you have tried and exactly where you are stuck.

Please follow the rules of posting in this forum, as enunciated at:

READ BEFORE POSTING​

Please share your work/thoughts about this problem.

 

[Steven G]

Why do you think that there is a formula when working a math problem. You need to think about it.

So you are NOT selling the item for £100!

You get to keep 82% of the selling price. So you want to know 82% of what number is £100.

Give this a try and post back with your work.

 

[Mr. Bland]

How is an 18% discount calculated? If [MATH]x[/MATH] is the starting price...

[MATH]f(x) = x * (100\% - 18\%)[/MATH]​

... then what is [MATH]x[/MATH] when [MATH]f(x) = 100[/MATH]?