Any way to get past this interview question?

My Friend went for an interview and the trader tested his maths. He asked what is 64 times 125?

My friend was stunned and tried to calculate manually in his mind and gave an answer. He went back and calculated and noted he got the wrong answer.

He went for another interview and the other trader asked him what is 32 times 32?

He again gave the wrong answer.

How does one get around maths questions like these? How can one improve their maths within a short span of time?

19 Comments
 

mental math isn't so hard to learn if you practice when you are totally relaxed, and its actually pretty useful (especially when shopping).

64 * 125 = 64 * 25 *5 = 1600 * 5 = 8000

32^2 = 2^10 = 1024 (if you know a bit about binary)

I recommend "Secrets of Mental Math" by Benjamin. Learned a lot of cool tricks from him.

 

What a joke. Just because you can't do 3232 in your head doesn't mean you're not a good fit. It takes no more than 1 minute to learn the "trick" to doing 3232 or 32^2 or whatever. It's not, in anyway, a measure of your aptitude for the job. However, there is an argument to be made that you should know that a bank is going to ask you these questions beforehand, so you should have prepared adequately.

 
Judge ReinholdWhat a joke. Just because you can't do 3232 in your head doesn't mean you're not a good fit. It takes no more than 1 minute to learn the "trick" to doing 3232 or 32^2 or whatever. It's not, in anyway, a measure of your aptitude for the job. However, there is an argument to be made that you should know that a bank is going to ask you these questions beforehand, so you should have prepared adequately.

If it only takes 1 min to be good at mental maths, how come this guy didn't take 1 min in his past 20 years to do it ?

 
Judge ReinholdWhat a joke. Just because you can't do 3232 in your head doesn't mean you're not a good fit. It takes no more than 1 minute to learn the "trick" to doing 3232 or 32^2 or whatever. It's not, in anyway, a measure of your aptitude for the job. However, there is an argument to be made that you should know that a bank is going to ask you these questions beforehand, so you should have prepared adequately.

Lol or maybe you should have learned how to multiply in grade school?

 
Best Response
dabanobo
Judge ReinholdWhat a joke. Just because you can't do 3232 in your head doesn't mean you're not a good fit. It takes no more than 1 minute to learn the "trick" to doing 3232 or 32^2 or whatever. It's not, in anyway, a measure of your aptitude for the job. However, there is an argument to be made that you should know that a bank is going to ask you these questions beforehand, so you should have prepared adequately.

Lol or maybe you should have learned how to multiply in grade school?

honestly shut the fuck up. this is much different than multiplying in grade school you prick. there are obvious reasons why someone would get tripped up on these in an interview setting. yes, they aren't very difficult if you've read benjamins secrets to mental math (which any prospective SA should), but it's very easy to fuck this up when you have 45 seconds to compute it

 
ImperialianMy Friend went for an interview and the trader tested his maths. He asked what is 64 times 125?

My friend was stunned and tried to calculate manually in his mind and gave an answer. He went back and calculated and noted he got the wrong answer.

He went for another interview and the other trader asked him what is 32 times 32?

He again gave the wrong answer.

How does one get around maths questions like these? How can one improve their maths within a short span of time?

if you are familiar with numbers you know that 125*8 = 1000

For 3232, you know that 32 is a power of 2. So the result is also a power of 2. You also know that the result is around 1000, (3030=900) so the result is 1024...

 

Lot of good advice above. I've always been told to break it up but its tough. When I went through recruitment, I tried to use the tricks but still missed those type of questions

XX
 

This is a give me question. There was another thread where a similar question was discussed but the difficulty level was 1000x worse. It was like 653*857.

Easiest way to do this one...

(64*100)=6400 ....just tack on the two zero's

so now 25 is left from the 125.....so 1/4th of 6400? even easier....1600

boom 8000.

653*857 would be annoying

"I'm short your house"
 

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