You are given a question and two statements. Identify which of the statements is/are sufficient to answer the question.
Question:
What is the total age of the sisters 10 years from now?
Statements:
1. Lina is 20 years old now.
2. Lina's sister's age is twice the age of Lina.

Options

A. Statement 1 alone is sufficient.
B. Statements 1 and 2 together are not sufficient.
C. Statement 2 alone is sufficient.
D. Statements 1 and 2 together are sufficient.

Answer

To determine the total age of the sisters 10 years from now, we will analyze the information given in the statements step by step.

### Step 1: Analyze Statement 1
- **Statement 1** states that "Lina is 20 years old now."
- This gives us Lina's current age: **Lina's age = 20 years.**

### Step 2: Analyze Statement 2
- **Statement 2** states that "Lina's sister's age is twice the age of Lina."
- Since we know Lina's current age is 20 years, we can calculate her sister's current age:
- **Sister's age = 2 × Lina's age = 2 × 20 = 40 years.**

### Step 3: Calculate Ages in 10 Years
- Now, we need to calculate their ages 10 years from now.
- **Lina's age in 10 years = Current age + 10 = 20 + 10 = 30 years.**
- **Sister's age in 10 years = Current age + 10 = 40 + 10 = 50 years.**

### Step 4: Calculate Total Age in 10 Years
- Now, we can find the total age of both sisters in 10 years:
- **Total age = Lina's age in 10 years + Sister's age in 10 years = 30 + 50 = 80 years.**

### Conclusion
- The total age of the sisters 10 years from now is **80 years.**

### Summary of Statement Sufficiency
- **Statement 1** alone gives us Lina's age but does not provide information about her sister's age.
- **Statement 2** alone does not provide Lina's current age.
- **Both statements together** are necessary to determine the total age of the sisters in 10 years.