{"id":"fpa-tiered-price-revenue-lines","audience":"fpa","category":"finance-work","track":"finance","technique":"verification","level":"intermediate","title":"Price an order on marginal tiers and show the average price","free":false,"task":"You're quoting revenue on a volume-tiered price list. Write a prompt for plain text with lines starting \"First 100:\", \"Next 400:\", \"Last 150:\", \"Total:\" and \"Average price:\", each with the math. Tiers are marginal: each tier's price applies only to the units in that tier. Don't mention the sales rep's claim about all units at one price. Under 70 words. No bullets or numbering.","materialLabel":"Price tiers and an order (attached to your prompt automatically)","material":"VOLUME PRICING - Starter Kit, effective Oct 1, 2026\n\nTier 1: units 1 to 100 - $50.00 per unit\nTier 2: units 101 to 500 - $45.00 per unit\nTier 3: units 501 and above - $40.00 per unit\nTiers are marginal: each price applies only to the units that fall in that tier.\n\nOrder from Harbor Lane Bakery: 650 units.\n\nNotes: the sales rep told the customer 'everything over 500 gets the $40 price on all units', which is not what the price list says. Average price = total / units, to the cent.","rules":[{"type":"plainText"},{"type":"maxWords","max":70},{"type":"maxBullets","max":0}],"promptHints":[{"label":"Names the five lines","patterns":["first 100","next 400","last 150","total:","average price"]},{"label":"States marginal tiers","patterns":["marginal"]},{"label":"Asks for arithmetic","patterns":["arithmetic","units x"]},{"label":"Bans the rep's claim","patterns":["(do not|don'?t).*(rep|all.units)"]},{"label":"Caps length","patterns":["\\d+\\s*words","plain"]}],"mistakes":[{"title":"Pricing all units at $40","why":"The AI applies the lowest tier to the whole order: $26,000.","fix":"Say: \"Tiers are marginal; each price applies only to units in that tier.\"","checks":["r0","r2"]},{"title":"Echoing the rep","why":"The AI mentions the rep's all-units promise.","fix":"Add: \"Do not mention the rep's claim.\"","checks":["r2"]},{"title":"Average price error","why":"The AI averages the three tier prices.","fix":"Add: \"Average price = total / 650.\"","checks":["r2"]},{"title":"Markdown extras","why":"The AI adds bold labels, headings and a closing note.","fix":"Say: \"Plain text, no bold. Output only the lines asked for.\"","checks":["plainText","maxBullets","r1"]},{"title":"Trusting the AI to count words","why":"AI is bad at counting and runs past word limits.","fix":"Ask for fewer words than the real cap and keep each line short.","checks":["maxWords"]}],"hint":"Tier prices apply to units in the tier. State the marginal rule and the closing average.","rubricLabels":["The line starting \"First 100:\" shows 100 x $50 = $5,000 and the line starting \"Next 400:\" shows 400 x $45 = $18,000","The line starting \"Last 150:\" shows 150 x $40 = $6,000 and the line starting \"Total:\" shows $5,000 + $18,000 + $6,000 = $29,000","The line starting \"Average price:\" shows $29,000 / 650 = $44.62, and the output never mentions the rep's claim or an all-units $40 price"]}