40 dollars
40% off of 20 dollars = 60% of 20 dollars (100 - 40 = 60) = 20*60/100 = 12 dollars
20% of 40 dollars is 8 dollars. 40*0.2=8
20 dollars
20 dollars are 100 percent. You want 40 percent off, that means you want 60 percent. 20/100 = 0.2 is 1 percent that value times 60 gives the wanted 60 percent. You have to pay only 0.2 times 60 = 12 dollars instead of 20 dollars.
40 percent of 50 = $20
32 dollars
$40
20$ 80c
40% of 49 dollars = 49*40/100 = 19.6 dollars.
20 % of minus 200 dollars is minus 40 dollars.
280 dollars