(Biggest common factor of 5, 10 and 50) + (Smallest common multiple of 10, 20, 30) is equal to

Options

A. 60
B. 65
C. 70
D. 75

Answer

To solve the question, we need to find the Biggest Common Factor (BCF) of the numbers 5, 10, and 50, and the Smallest Common Multiple (SCM) of the numbers 10, 20, and 30. Then, we will add these two results together.

### Step 1: Find the Biggest Common Factor (BCF) of 5, 10, and 50

1. **List the factors of each number:**
- Factors of 5: 1, 5
- Factors of 10: 1, 2, 5, 10
- Factors of 50: 1, 2, 5, 10, 25, 50

2. **Identify the common factors:**
- Common factors of 5, 10, and 50: 1, 5

3. **Determine the biggest common factor:**
- The biggest common factor is 5.

### Step 2: Find the Smallest Common Multiple (SCM) of 10, 20, and 30

1. **List the multiples of each number:**
- Multiples of 10: 10, 20, 30, 40, 50, 60, ...
- Multiples of 20: 20, 40, 60, 80, ...
- Multiples of 30: 30, 60, 90, ...

2. **Identify the common multiples:**
- Common multiples of 10, 20, and 30: 60, 120, ...

3. **Determine the smallest common multiple:**
- The smallest common multiple is 60.

### Step 3: Add the BCF and SCM

1. **Add the results from Step 1 and Step 2:**
- BCF (5) + SCM (60) = 5 + 60 = 65

### Final Answer

The final answer is **65**.

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