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NBT Quantitative Literacy: Percentages and Financial Mathematics Flashcards

6 cards from real NBT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 6 NBT Quantitative Literacy: Percentages and Financial Mathematics flashcards as text

  1. A retailer marks up a jacket by 25% above cost price, then offers a 20% discount in a sale. What is the net percentage change in price compared to the original cost price?

    Answer: 0% — the price returns exactly to cost

    Applying both changes sequentially: Cost × 1.25 × 0.80 = Cost × 1.00. The two operations cancel exactly, so the final price equals the original cost price — a 0% net change. A common error is to simply subtract 20% from 25% and conclude a 5% increase, but percentage changes must be multiplied, not added or subtracted.

  2. R15,000 is invested at 9% per annum compounded monthly. What is the accumulated value after 3 years? (Round to the nearest cent.)

    Answer: R19,629.68

    Using A = P(1 + i/n)^(nt): A = 15,000 × (1 + 0.09/12)^(12×3) = 15,000 × (1.0075)^36. Calculating (1.0075)^36 ≈ 1.308645, so A ≈ R19,629.68. Option A uses simple interest (15,000 + 15,000×0.09×3 = R19,050). Option B compounds annually (15,000×1.09³ ≈ R19,425.44). Monthly compounding yields the highest return because interest is earned on interest more frequently.

  3. A customer pays R1,725 for a television set. This price includes VAT at 15%. What is the rand amount of VAT included in the price paid?

    Answer: R225.00

    The VAT-inclusive price equals the ex-VAT price × 1.15. To extract VAT: VAT = R1,725 × (15/115) = R1,725 × (3/23) = R225.00. Option A (R258.75) is the most common error — calculating 15% of the inclusive price (R1,725 × 0.15) instead of reversing the VAT. The VAT fraction must always be 15/115, not 15/100.

  4. Thabo earns a nominal interest rate of 11% per annum on his savings account. Annual inflation is 7%. Using the exact Fisher equation, what is his real rate of return?

    Answer: 3.74%

    The Fisher equation states: (1 + real rate) = (1 + nominal rate) / (1 + inflation rate). So: (1 + r) = 1.11 / 1.07 ≈ 1.03738, giving r ≈ 3.74%. Option A (4.00%) uses the simple approximation of subtracting inflation from the nominal rate (11% − 7%), which overestimates the real return. Option D incorrectly adds the rates. The exact formula is required for precision.

  5. A laptop priced at R9,600 is purchased on hire purchase. A 25% deposit is paid upfront, and the balance is financed over 24 months at 15% per annum simple interest. What is the monthly instalment?

    Answer: R390.00

    Deposit = 25% × R9,600 = R2,400. Balance financed = R9,600 − R2,400 = R7,200. Simple interest on balance = R7,200 × 0.15 × 2 = R2,160. Total to repay = R7,200 + R2,160 = R9,360. Monthly instalment = R9,360 ÷ 24 = R390.00. Option A (R300) forgets to add interest (R7,200 ÷ 24). Option C (R420) incorrectly calculates interest on the full purchase price of R9,600 rather than the financed balance.

  6. A car is purchased for R280,000 and depreciates at 18% per annum on a reducing balance basis. What is its book value at the end of 3 years?

    Answer: R154,383.04

    Reducing balance depreciation is calculated as V = P × (1 − d)^n. V = 280,000 × (0.82)³. Year 1: 280,000 × 0.82 = R229,600. Year 2: 229,600 × 0.82 = R188,272. Year 3: 188,272 × 0.82 = R154,383.04. Option A (R128,800) results from straight-line depreciation (280,000 × 0.18 × 3 = R151,200; book value = R128,800) — a fundamentally different method that applies the same depreciation amount each year rather than to the declining value.