Answer:
$400
Step-by-step explanation:
Given: A number is decreased by 70% to 120.
Lets assume the original number be "x".
∴ Forming an equation to show number decrease to 120.
⇒ [tex]x-70\% \times x= 120[/tex]
Now solving it to find the value of x
⇒[tex]x-0.70x= 120[/tex]
⇒ [tex]0.3x= 120[/tex]
Dividing both side by 0.3
⇒ [tex]x= \frac{120}{0.3}[/tex]
∴[tex]x= 400[/tex]
Hence, The original amount is $400.