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Problem #84 · October 19, 2026

EKUB — greatest common divisor and EKUK — least common multiple

Find the greatest common divisor of the numbers 60, 84 and 120.
  1. A4
  2. B6
  3. C8
  4. D12
  5. E24

WORKED EXAMPLE

Solution

60=22⋅3⋅560 = 2^2 \cdot 3 \cdot 5, 84=22⋅3⋅784 = 2^2 \cdot 3 \cdot 7, 120=23⋅3⋅5120 = 2^3 \cdot 3 \cdot 5. The prime factors present in all three numbers are 2 and 3, and their lowest powers are 222^2 and 313^1. Therefore EKUB =22⋅3=12= 2^2 \cdot 3 = 12.
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