7 ms·

Another way to answer this kind of question is to know 2^24 = 2^10 * 2^10 * 2^4 and that 2^10 is 1024 which is roughly 1000. So 1000 * 1000 * 16 = 16 million w

Another way to answer this kind of question is to know 2^24 = 2^10 * 2^10 * 2^4 and that 2^10 is 1024 which is roughly 1000. So 1000 * 1000 * 16 = 16 million would be an easy estimate to make. If you are designing a system and want to have an idea of how much space or memory an approach will take, being good at this kind of math can be really helpful.

lomnakkus 10y ago
Then they should probably ask people to estimate a thing that's even remotely relevant to the job. (I mean, I get it, this kind of general estimation and/or ball-parking can be incredibly valuable, but this doesn't sound relevant in any way.)
- kafkaesq 10y ago
  This kind of general estimation and/or ball-parking can be incredibly valuable, but this doesn't sound relevant in any way. To be fair to Google (in regard to this one filter question only), they actually are up front about expecting a significantly higher baseline of general mathematical awareness (even for non-mathy roles) than most other shops. At any rate, this kind of estimation comes up in capacity planning (both in architecture planning, and for algorithms on a single box) all the time. Which after all is what Google does, at nearly every level of their stack, (nearly) all the time.
  - lomnakkus 10y ago
    It "comes up all the time"... and these ballpark guesses are probably(!) completely useless for anything remotely practical. At the scale Google's operating you want a Statistician, not a Guesstimator. So, no, still not useful questions.
jameshart 10y ago
The problem is that there are some people who will need to go through that process in their head to produce an estimate of 16 million - and then there are people who have had cause at some point in their life to know of the existence of the concept of '24 bit color' and that the number of colors expressible in 24 bits (8 bits each of R, G and B) is exactly 16,777,216.

lomnakkus 10y ago

Then they should probably ask people to estimate a thing that's even remotely relevant to the job. (I mean, I get it, this kind of general estimation and/or ball-parking can be incredibly valuable, but this doesn't sound relevant in any way.)

kafkaesq 10y ago
This kind of general estimation and/or ball-parking can be incredibly valuable, but this doesn't sound relevant in any way. To be fair to Google (in regard to this one filter question only), they actually are up front about expecting a significantly higher baseline of general mathematical awareness (even for non-mathy roles) than most other shops. At any rate, this kind of estimation comes up in capacity planning (both in architecture planning, and for algorithms on a single box) all the time. Which after all is what Google does, at nearly every level of their stack, (nearly) all the time.
- lomnakkus 10y ago
  It "comes up all the time"... and these ballpark guesses are probably(!) completely useless for anything remotely practical. At the scale Google's operating you want a Statistician, not a Guesstimator. So, no, still not useful questions.

jameshart 10y ago

The problem is that there are some people who will need to go through that process in their head to produce an estimate of 16 million - and then there are people who have had cause at some point in their life to know of the existence of the concept of '24 bit color' and that the number of colors expressible in 24 bits (8 bits each of R, G and B) is exactly 16,777,216.