Question

How do you decrease 50 by 10%?

Answer 1

Hint: In this question we have to find the decrease of the number by the given percentage, to find the decrease we will use the formula, Percentage decreased number = Initial value – (Percentage decrease % × Initial value ) which is again equal to (1 - Percentage decrease %) × Initial value , now substituting the values we get the required result.

Complete step by step solution:
The percentage is defined as how much of one quantity is made by another quantity and it is evaluated in terms of 100. A percentage is a number that is represented as a fraction of 100.
When the new value is lesser than the original value. The percent change in the value signifies the percentage decrease in the original number such that,
Percentage decrease %$ = \dfrac{{{\text{Decrease in value}}}}{{{\text{original value}}}} \times 100$, and
Here ${\text{Decrease in value = Original value}} - {\text{New value}}$,
And Percentage decreased number = Initial value - Percentage decrease % × Initial value = (1 - Percentage decrease %) × Initial value
Given that we have to decrease 50 by 10%,
Now here percentage % = 10, initial value = 50 and substituting the value we get,$ \Rightarrow {\text{Percentage decreased number = 50}} - 10\% {\text{ of 50}}$,
Now simplifying we get,
$ \Rightarrow {\text{Percentage decreased number = 50}} - \dfrac{{10}}{{100}} \times {\text{ 50}}$,
Now simplifying we get,
$ \Rightarrow {\text{Percentage decreased number = 50}} - \left( {1 \times 5} \right)$,
Now multiplying we get,
$ \Rightarrow {\text{Percentage decreased number = 50}} - 5$,
Now finally by subtracting we get,
$ \Rightarrow {\text{Percentage decreased number = 45}}$
So, the decrease of 10% of 50 will be 45.

$\therefore $ The decrease of 10% of 50 will be equal to 45.

Note: The percentage is the result when a specific number is multiplied by a percent. Most of the time, percentages are smaller than the number since a percentage is a portion of a number or quantity. But there are cases where the percentage is greater than the number. This would happen if the percent is greater than 100% i.e., a percentage is a certain percent of a number, and most of the time, the quantity is followed by the phrase "percent of" which is represented as “%”.