Let’s solve each question step by step.
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Question 1: Find the geometric mean of 8 and 18.
Geometric mean of two numbers = √(a × b)
So, √(8 × 18) = √144 =
12
✔ Correct answer:
D. 12
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Question 2: Find the geometric mean of 20 and 25.
√(20 × 25) = √500
Simplify √500:
500 = 100 × 5 → √100 × √5 =
10√5
✔ Correct answer:
B. 10√5
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Question 3: 15 is the geometric mean of 25 and what other number?
Let the unknown number be x.
Then: √(25 × x) = 15
Square both sides:
25x = 225
→ x = 225 ÷ 25 =
9
✔ Correct answer:
C. 9
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Question 4: Find the geometric mean of 3 and 7.
√(3 × 7) = √21
✔ Correct answer:
A. √21
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Question 5: 32 is the geometric mean of 16 and what other number?
Let the unknown number be x.
√(16 × x) = 32
Square both sides:
16x = 1024
→ x = 1024 ÷ 16 =
64
✔ Correct answer:
B. 64
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Question 6: Find the geometric mean of 12 and 27.
√(12 × 27) = √324
What’s √324? 18 × 18 = 324 → so √324 =
18
✔ Correct answer:
C. 18
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Question 7: The geometric mean of 4 and ______ is 6. What is the missing number?
Let the missing number be x.
√(4 × x) = 6
Square both sides:
4x = 36
→ x = 36 ÷ 4 =
9
✔ Missing number is
9
*(Note: This question doesn’t have multiple choice options shown in your image, but based on calculation, the answer is 9.)*
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Final Answer:
1. D
2. B
3. C
4. A
5. B
6. C
7. 9
Parent Tip: Review the logic above to help your child master the concept of geometric mean practice worksheet.
