If you can't get the answer in the usual manner, start at the answer and derive the question. If that doesn't work, start at both ends and try to find a common middle. In case of doubt, make it sound convincing. Team work is essential. It allows you to blame someone else.
All unmarked beakers contain fast-acting, extremely toxic poisons.
I haven't bothered to check the references. Each element is worth one dollar. Underline the number 20. There are no wrong answers. Assume capital gains are no longer taxed, because this encourages investment.