A salesperson received a commission of 3 percent of the sale price for each of the first 100 machines that she sold and 4 percent of the sale price for each machine that she sold after the first 100. If the sale price of each machine was $10,000 and the salesperson received a $42,000 commission, how many machines did she sell?  Pick:
A) 90
B) 103
C) 130
D) 115
E) 120

Rationale: first 100 machines = 3 % commission = 0.03 * 100 * 10000 = 30000 commission from sale of next machines = 42000 - 30000 = 12000 so 30 more machines . . total = 130 machines imo c . . .
Answer: C