Answer:
$142,858
Explanation:
You want to know the sales amount that would give a salary option of $16,000 in base pay with a 12% commission a larger income than a salary option of $26,000 in base pay with a 5% commission.
Income
Your income in each salary plan is ...
plan A = 16000 +0.12s . . . . . . for s dollars in sales
plan B = 26000 +0.05s
Comparison
For plan A to produce a greater income than plan B, you want ...
plan A > plan B
16000 +0.12s > 26000 +0.05s
0.07s > 10000 . . . . . . . . subtract 16000+0.05s
s > 142857.1429
You would need to sell at least $142,858 of jewelry each year.
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Additional comment
We have rounded up to the nearest dollar, so that this amount of sales will result in a larger income under plan A. If we were to round (down) to dollars or to cents, the amount would actually give a smaller income under plan A.