Choose the correct alternative from the options given below to replace the…
2013
Choose the correct alternative from the options given below to replace the question mark (?) in the puzzle diagram:
- A.
60
- B.
50
- C.
25
- D.
35
Attempted by 14 students.
Show answer & explanation
Correct answer: C
In each tree, the bottom number equals the product of the square roots of the two top numbers (i.e. the geometric-mean rule: bottom = √(top-left) × √(top-right)).
Check: √4 × √9 = 2 × 3 = 6, and √9 × √16 = 3 × 4 = 12.
Apply the same rule to the third tree: √16 × √? = 20 → 4 × √? = 20 → √? = 5 → ? = 25.