The formula is B X R or base X rate..for example.. the base is 50 then the rate is 30 %...first, you will change the percent into decimal... it will become 0.30 .... you just need to moved two decimal places going to the left.. after that, you will multiply 50 ( which is the base) and 0.30 ( which is the rate that turn into decimal)... the answer will become 15.. that is your percentage :)

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Percentage equals the product of the base and the rate. That is, P = B x R where B is the base and R is the rate.