WAEC 2024 Mathematics · Question 4
Multiply 3.4 x 10 by 7.1 x 10 and leave the answer in standard form.
Options
- A.2.414 x 10
- B.2.414 x 10
- C.2.414 x 10
- D.2.414 x 10
Answer: C. 2.414 x 10
Explanation written with AI and checked against the answer key
Step 1: Analyze the question We need to multiply two numbers written in standard form and give the answer in standard form (a × 10ⁿ, where 1 ≤ a < 10). Step 2: Concept Multiply the decimal parts, then add the powers of 10: (a × 10ᵐ) × (b × 10ⁿ) = (a × b) × 10^(m+n) Step 3: Solution Multiply the decimal parts: 3.4 × 7.1 = 24.14 Add the powers of 10: 10⁻⁵ × 10⁸ = 10^(−5+8) = 10³ Combine: 24.14 × 10³ 24.14 is not between 1 and 10, so convert it: 24.14 = 2.414 × 10¹ So: 2.414 × 10¹ × 10³ = 2.414 × 10⁴ Step 4: Answer The result is 2.414 × 10⁴, which is option C. Tip: After multiplying the decimal parts, always check whether the result is still between 1 and 10. If it is 10 or more, shift the decimal point left and increase the power of 10 by one for each place you move. Many students stop at 24.14 × 10³ and lose the mark.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.