1. **State the problem:** Find the least common multiple (LCM) of 72 and 120. 2. **Recall the formula:** The LCM of two numbers $a$ and $b$ can be found using their greatest common divisor (GCD) as: $$\text{LCM}(a,b) = \frac{|a \times b|}{\text{GCD}(a,b)}$$ 3. **Find the prime factorizations:** - $72 = 2^3 \times 3^2$ - $120 = 2^3 \times 3 \times 5$ 4. **Find the GCD:** - The GCD takes the minimum powers of common primes: - $\text{GCD}(72,120) = 2^3 \times 3^1 = 8 \times 3 = 24$ 5. **Calculate the LCM:** $$\text{LCM}(72,120) = \frac{72 \times 120}{24}$$ 6. **Simplify the fraction:** $$= \frac{\cancel{24} \times 3 \times 120}{\cancel{24}} = 3 \times 120 = 360$$ 7. **Answer:** The least common multiple of 72 and 120 is **360**. Therefore, the correct choice is **B 360**.