A number is multiplied by 7, then 9 is added, and the result is halved. The answer is 22. What was the number?
Answer and explanation
Correct answer: B. 5
- Step 1: Work backwards. Undo the halving: 22 × 2 = 44. Step 2. Undo the addition: 44 - 9 = 35. Step 3. Undo the multiplication: 35 ÷ 7 = 5. Answer: 5. Why not the others: 6.29: This forgets to subtract 9 before dividing by 7, giving 44 ÷ 7. 7.57: This adds 9 instead of subtracting it when working backwards, giving 53 ÷ 7. 1.86: This forgets to double 22 first, giving (22 - 9) ÷ 7.
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