Answer:
$36
Explanation:
Since 30% = 30/100 then we can transform it into a decimal:
30%=0.30
Now if we multiply 120•0.30, we will get how much we saved.
$36, we saved $36.
Bonus information:
If the problem was to say "How much does the cell phone cost after the discount?", then you would multiply 120•0.70.
Hope this helps! If you have any questions on how I got my answer feel free to ask. Stay safe!