This month’s brain teaser comes from one of our students! It’s a question that one of her colleagues asks people in job interviews. So, lest you think that pondering brain teasers (especially confusingly worded and seemingly inane ones like the below) are a waste of time, think again!!!
If a brick weighs one pound and half a brick, how many pounds does a brick weigh?
Answer:
Ok, admittedly, this is worded in a deliberately confusing way, and many people find it hard to wrap their heads around the question. However, lest you think you’ll never be faced with something so silly, this is the kind of question you could get in a banking or consulting interview!
There are at least a couple of ways to solve it.
First, you could use algebra. If b equals the weight of 1 brick, then we can say that b = 1 + ½ b. Then, solving for b, you get ½ b = 1, so b = 2.
However, you could also approach the question more logically and intuitively. If a brick weighs 1 pound + half a brick, then that 1 pound represents the other half of the brick, right? Afterall, a brick must be composed of 2 halves. So one half is the “half a brick” that we’re given and the other half is the “1 pound.” So, if 1 pound IS half of the brick, then the brick weighs 2 pounds.