NBT case studies
NBT · Put your knowledge to work in context.
The National Benchmark Tests (NBTs) are administered through the National Benchmark Test Project. The official NBT site presents an AQL option and an AQL & MAT option, and publishes fees for each as well as a re-mark fee. It provides applicant guidance on booking a test, test dates, test venues, what to expect, and accessing or requesting results. The site also has sections for educators and institutions, including placement testing and national reports covering multiple years. Topics on this exam: Academic and Quantitative Literacy (AQL) and Mathematics (MAT). The NBT case studies are 5 cases and about 3,478 words.
1Clinic Positivity: A Rising Rate That Isn't
A district clinic reports on its HIV counselling-and-testing programme. In 2023 it tested 1 200 people and recorded 96 positive results. In 2024 it tested 1 500 people and recorded 150 positive results. In January 2024 the clinic began actively recruiting clients from two high-risk groups - long-distance drivers and sex workers - who had not previously been targeted.
648 words, about 3 min2Nomsa's Taxi Fares: The Bundle That Can Never Win
Nomsa travels to work by minibus taxi. A single trip costs R32 and she makes two trips on every day she goes to the office. In a typical month there are 22 working days, and she works from home on 6 of them. Three payment options exist: (a) pay R32 per single trip; (b) buy a monthly unlimited ticket for R780; (c) buy a 30-trip pack for R840, valid for that month only, with unused trips forfeited.
695 words, about 3 min3The Leaking Tank: Why Doubling the Pump Doesn't Halve the Time
An off-grid household stores water in a rectangular tank with internal dimensions 1,20 m long, 0,80 m wide and 1,50 m deep. A borehole pump feeds the tank at a steady 15 litres per minute. A leaking outlet valve loses water at a constant 3 litres per minute whenever the tank holds water. At 06:00 on Monday the tank holds 300 litres and the pump is switched on; it runs continuously.
611 words, about 3 min4Two Campuses, One Stagnant Pass Rate
A university publishes first-year pass rates for two campuses. In 2023, Campus A enrolled 400 first-year students and 80% passed; Campus B enrolled 100 and 60% passed. In 2024, Campus A enrolled 200 first-year students and 85% passed, while Campus B enrolled 300 and 70% passed. A newspaper headline reads: "Pass rate stuck at 76% - nothing has changed in two years." The dean of Campus B objects: "Our pass rate rose by ten percentage points, the biggest improvement in the institution, yet we are blamed for the stagnation." A senate member responds by proposing that the university shift more students to Campus A, since Campus A's pass rate is higher in both years.
720 words, about 4 min5Three Data Bundles: The Average-Cost Trap
A prepaid data provider offers three bundles. Option X: no monthly fee, R0,29 per megabyte used. Option Y: R30 per month for the first 200 MB, then R0,35 per megabyte for every megabyte beyond 200. Option Z: R120 per month for unlimited data.
804 words, about 4 min