Word Problems

[swerve]

If Alyssa is twice as old as Brandon, by how many years is Brandon older than Clara?

1) Four years ago, Alyssa was twice as old as Clara is now
2) Alyssa is 8 years older than Clara

The OA is A

Source: Veritas Prep

[Ian Stewart]

Using Statement 1 alone, we know if we double Brandon's age and double Carla's age, we get two numbers that are 4 apart. When you double two positive numbers, you double their difference, so Brandon's age and Carla's age must be 2 apart, and Statement 1 is sufficient alone. Or you could see that algebraically, by subtracting the second equation below from the first:

2B = A
2C = A - 4

to get:

2B - 2C = 4
B - C = 2

Statement 2 is not sufficient, as any two numerical examples will show, so the answer is A.