How to decrease the number 42
by - 17% of its value?
Value of Percentage Decrease. New Value
- A percentage value is nothing but a fraction with a denominator of 100:
- - 17% = - 17/100 = - 17 ÷ 100 = - 0.17
- ...
- To decrease a positive number, subtract from it the 'Value of Percentage Decrease'.
- To decrease a negative number, don't subtract from it, but add to it the 'Value of Percentage Decrease'.
- ...
Value of Percentage Decrease =
Percentage of the Decrease % × The original value =
- 17% × 42
New Value =
The original value - Value of Percentage Decrease =
42 - (- 17% × 42)
1. Calculate the End Value
decreased by a percentage of its Initial Value
End Value =
42 - Value of Percentage Decrease =
42 - (- 17% × 42) =
42 + 17% × 42 =
(42 is a common factor)
(1 + 17%) × 42 =
(100% + 17%) × 42 =
117% × 42 =
117 ÷ 100 × 42 =
117 × 42 ÷ 100 =
4,914 ÷ 100 =
49.14
2. Value of Percentage Decrease
It can be calculated in two ways.
The first method:
Value of Percentage Decrease =
Percentage of the Decrease % × The original value =
- 17% × 42
The second method:
Value of Percentage Decrease =
The original value - New Value
Value of Percentage Decrease =
- 7.14
The value of the decrease is negative, so we are actually dealing with a Percentage Increase.
The end value: 42 decreased by - 17% percent = 49.14
Value of Percentage Decrease = - 7.14