,Okay, so here is how to calculate the amount of the trade discount:
I: $149,500 * .10 (10%) = 14,950 (this is the 10% discount)
149,500 - 14,950 = 134,550 (how much it costs with a 10% discount)
II: 134,550 * .5 (5%) = 6727.50
134,550 - 6727.50 = 127,822.50
III: 127,822.50 * .4 (4%) = 5112.90
The amount of the trade discount is: $14,950 + $6727.50 + $5112.90 = 26,790.40 dollars.