Final answer:
The saleswoman earned $360 commission last month.
Step-by-step explanation:
To calculate the commission earned by the saleswoman, we need to multiply her sales by the commission rate.
Since she earns a 60% commission on all the merchandise she sells, we can calculate her commission by multiplying $600 (the amount of merchandise sold) by 0.60 (the commission rate):
Commission earned = $600 * 0.60 = $360
Therefore, the saleswoman earned $360 commission last month.