WAEC 2011 Mathematics · Question 19
If N112.00 exchanges for D14.95, calculate the value of D1.00 in naira
Options
- A.0.13
- B.7.49
- C.8.00
- D.13.00
Answer: B. 7.49
Explanation written with AI and checked against the answer key
Analyze the question: We are told that N112.00 = D14.95 (naira to dalasi). We need the naira value of D1.00.
Concept: To find the value of one unit of a currency, divide the naira amount by the number of units it buys.
Solution:
D14.95 = N112.00
D1.00 = N112.00 ÷ 14.95
Estimate: 14.95 ≈ 15, and 112 ÷ 15 ≈ 7.47.
Exact calculation:
- 14.95 × 7 = 104.65
- 112 − 104.65 = 7.35
- 7.35 ÷ 14.95 ≈ 0.49
So 112 ÷ 14.95 ≈ 7.49
Check: 14.95 × 7.49 = 111.98, which is approximately 112. ✔
Answer: D1.00 ≈ N7.49, which is option B.
Why not the others?
- A (0.13) is 14.95 ÷ 112, which is the value of N1 in dalasi (the inverse).
- C (8.00) and D (13.00) do not match the calculation.
Tip: Always check which currency you are converting to. If you want "1 unit of X in terms of Y", divide Y's amount by X's amount. A quick estimate (rounding 14.95 to 15) helps you rule out wrong options fast.
AI can make mistakes. Report anything that looks wrong.
Past questions © the examination body (JAMB/WAEC/NECO). DeeepSolve is not affiliated with them. Rights holders: see /copyright.
