Question

What is 3 increased by 250%? Decreased by 100%? Decreased by 150%?

Answer 1

a) 3*3.5=10.5

b)3*0=0

c)3*-0.5=-1.5

Answer 2

Part A: Number 3 increased by 250% = 10.5

Part B: Number 3 decreased by 100% = 0

Part C: Number 3 decreased by 150% = -1.5

Explanation:

To calculate the increase or decrese

Let the original number is x and percentage increase or decrese is r%

So, of the number x is increased by r %:

The increase or the decrease will be ⇒
`x *(r)/(100)`

The number after the increase will be
`x+ x *(r)/(100) = x( 1+(r)/(100) )`

The number after the decrease will be
`x- x *(r)/(100) = x( 1-(r)/(100) )`

For the g iven question:

Part A: What is 3 increased by 250%?

x=3 , r =250 ⇒
`3( 1+(250)/(100) )` = 3 * 3.5 = 10.5

Part B: What is 3 Decreased by 100%?

x=3 , r =100⇒
`3( 1-(100)/(100) )` = 3 * 0 = 0

Part C: What is 3 Decreased by 150%?

x=3 , r =100⇒
`3( 1-(150)/(100) )` = 3 * -0.5 = -1.5