Explanation:
Given
SP = 210
profit percent (p%) = 5%
CP = X = ?
We know
Cost price (CP)
![= (sp \: * 100)/(100 + p\%) \\ = (210 * 100)/(100 + 5) \\ = (21000)/(105) \\ = 200](https://img.qammunity.org/2022/formulas/mathematics/high-school/94otztcspcucify1g9acbal7af1qdt2yic.png)
hope it helps :)❤
Or in another way
Let the cost price be x then
Profit amount
= 5 % of CP
= 5/100 * x
= x / 20
Selling Price (SP)
210 = CP + Profit amount
210 = x + x / 20
210 = ( 20x + x) / 20
210 * 20 = 21x
4200 = 21x
x = 4200 / 21
x = 200
Therefore CP = 200
Hope you understood.