15 percent off of 399 results in 339.15
399 x 0.7 = 279.30
359.10
359.10
99.75
75 percent of 100 is 75 75 percent off 100 is 25.
0.188
20% off of 399 = 399 - (0.20 x 399) = 319.2
387 is 75 percent off 516.
75 percent off of 29.99 is 22.49.
40% off I'm assuming that 60% remains. .60 x $399 = $239.60 is the remaining value $399 - $239.60 = $159.40 is the reduction in value
30 percent off 75 = 52.530% off of 75= 30% discount applied to 75= 75 - (30% * 75)= 75 - (0.30 * 75)= 75 - 22.5= 52.5