What is the Highest Common Factor of 12, 36 and 240
2024
What is the Highest Common Factor of 12, 36 and 240
- A.
12
- B.
30
- C.
18
- D.
480
Attempted by 164 students.
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Correct answer: A
To find the Highest Common Factor (HCF)—also known as the Greatest Common Divisor (GCD)—of 12, 36, and 240, we identify the largest number that divides all three numbers without leaving a remainder.
Step-by-Step Calculation (Prime Factorization Method)
Prime Factorize each number:
12 = 2 × 2 × 3 = 2² × 3¹
36 = 2 × 2 × 3 × 3 = 2² × 3²
240 = 2 × 2 × 2 × 2 × 3 × 5 = 2⁴ × 3¹ × 5¹
Identify common prime factors:
The common prime factors present in all three numbers are 2 and 3.
Select the lowest exponent for each common factor:
For the prime factor 2, the lowest exponent among 2², 2², and 2⁴ is 2².
For the prime factor 3, the lowest exponent among 3¹, 3², and 3¹ is 3¹.
Calculate the HCF:
HCF = 2² × 3¹ = 4 × 3 = 12