{"id":"fpa-opex-ratio-restated-trend","audience":"fpa","category":"finance-work","track":"finance","technique":"verification","level":"beginner","title":"Compute opex as a percent of revenue with a restated quarter","free":false,"task":"You're showing the opex ratio trend to the CFO. Write a prompt for plain text with lines starting \"Q1:\", \"Q2:\", \"Q3:\" and \"Change Q1 to Q3:\". Each quarter line shows opex / revenue = percent to one decimal, with the numbers in $M. Use the restated Q2 opex. The last line is the change in percentage points. Under 60 words. No bullets or numbering. Do not mention the CEO or whether the ratio improved every quarter.","materialLabel":"Quarterly revenue and opex (attached to your prompt automatically)","material":"OPEX RATIO INPUTS - Pinecrest Software, FY26 ($ millions)\n\nQuarter | Revenue | Opex (as first reported)\nQ1 | 4.0 | 2.20\nQ2 | 4.4 | 2.30\nQ3 | 4.8 | 2.40\n\nRestatement (controller, Oct 28): Q2 opex was understated by 0.12 because a vendor invoice was missed. Restated Q2 opex is 2.42. Q1 and Q3 are unchanged.\n\nNote: the CEO said at the all-hands 'opex ratio is improving every quarter'. That claim hasn't been checked against the restated number.","rules":[{"type":"plainText"},{"type":"maxWords","max":60},{"type":"maxBullets","max":0}],"promptHints":[{"label":"Names the four lines","patterns":["q1:","q2:","q3:","change q1 to q3"]},{"label":"Uses restated Q2","patterns":["restated","2\\.42"]},{"label":"Gives the formula","patterns":["opex / revenue"]},{"label":"Skips the CEO claim","patterns":["(do not|don'?t).*(comment|claim)"]},{"label":"Caps length","patterns":["\\d+\\s*words","plain"]}],"mistakes":[{"title":"Using first-reported Q2","why":"The AI uses 2.30 and shows 52.3%.","fix":"Say: \"Use the restated Q2 opex of 2.42.\"","checks":["r0"]},{"title":"Dividing revenue by opex","why":"The AI flips the ratio.","fix":"Add: \"opex / revenue = percent.\"","checks":["r1"]},{"title":"Echoing the CEO","why":"The AI says the ratio improved every quarter.","fix":"Add: \"Do not comment on the CEO's claim.\"","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"]},{"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":"A restated number changes the story. Name the figure to use, the formula and the four lines.","rubricLabels":["The line starting \"Q1:\" shows 2.20 / 4.0 = 55.0% and the line starting \"Q2:\" shows the restated 2.42 / 4.4 = 55.0%","The line starting \"Q3:\" shows 2.40 / 4.8 = 50.0%","The line starting \"Change Q1 to Q3:\" shows 50.0 - 55.0 = -5.0 points, and no line says the ratio improved every quarter, and the output never mentions the CEO or says the ratio improved every quarter"]}