1. **Find the L.C.M of 10, 15, and 25.** The Least Common Multiple (L.C.M) of numbers is the smallest number that is a multiple of all the given numbers. 2. **Prime factorize each number:** - 10 = $2 \times 5$ - 15 = $3 \times 5$ - 25 = $5^2$ 3. **Take the highest powers of all prime factors:** - For 2: highest power is $2^1$ - For 3: highest power is $3^1$ - For 5: highest power is $5^2$ 4. **Multiply these together:** $$\text{LCM} = 2^1 \times 3^1 \times 5^2 = 2 \times 3 \times 25 = 150$$ **Answer: C. 150**