Question

When a number is decreased by 40% of itself, the result is 90. What is the number?

Answer 1

Hello There, today we will solve your problem

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Definitions

Percentage - In mathematics, a percentage is a number or ratio expressed as a fraction of 100. It is often denoted using the percent sign, "%"

Solve

we can substitute 40% for 0.4x and make an equation

`x-0.4=90`

simplify

`0.6x=90`

divide both sides by 0.6

`x=150`

Answer 2

• Let the number be 'x'.



• Then, 40% of x -

= 40/100 × x

= 2/5 × x

= 2x/5


• Now, decreased number -

= x - 2x/5

= (5x - 2x)/5

= 3x/5



• But, according to the question, decreased number = 90

=> 3x/5 = 90

=> x = 90 × 5/3

=> x = 450/3

=> x = 150

• Hence, the number is 150



• Now, if 150 is increased by 40% -

= 150 + 40% of 150

= 150 + 40/100 × 150

= 150 + 4 × 15

= 150 + 60

= 210