1550.26 – Brick on a 2-Pan Scale

Tags:Problem Set 7Algebra IAlgebra

While watching a demonstration of how a 2-pan scale works, we notice that a brick placed on one side exactly balances 3/4 of a kg plus 3/4 of a brick on the other side. If this is so, what does the brick weigh?


Let b represent the weight of the brick.

Then b = 3/4 + 3/4b → 4b = 3 + 3b → b = 3.

Check: 3 = 3/4 + 3/4 · 3 = 3/4 + 9/4 = 12/4 = 3.

We, the Stella crew, try to make problems that might have some basis in reality. Alas, this is not such a problem. It is unimaginable that we would notice anything like what the problem claims we would notice within the context of a demonstration. Furthermore, we have been lax in neglecting to weigh an actual brick so as to use its real weight in the problem. Nonetheless, the problem is here, to be grappled with.