The Question:

 A married couple are gathering seashells. The wife says, "Give me seven of your shells and I will have twice as many as you!" The husband answers, "Give me seven of yours and we'll have the same amount!" How many seashells does each one have?

The Options:

The wife has 12, the husband 5

The wife has 16, the husband 9

The wife has 49, the husband 35

The wife has 51, the husband 37

The Answer:

The wife has 49, the husband 35

How was that derived:

If the husband gives the wife 7 shells, he'll have 28 and she'll have 56. She'll have twice as many as he does.

If the wife gives the husband 7 shells, she'll have 42 and he'll have 42.