Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

I tried to do everything I could, but I don't know what to do with that floor.

$58 = y\cdot\left[\frac{80}{y}\right]$

Where $[x]$ is floor function.

share|improve this question

1 Answer 1

up vote 5 down vote accepted

HINT:

So, $\frac{58}y= \left[\frac{80}{y}\right] $ which is an integer

$\implies y$ must divide $58$

share|improve this answer
    
Ok, now I know how to do my homework, but in freetime I'm a programmer and now I thought about a way of using it in my program, but I would need to do something to have y only on one side. Is it possible? If not then i'm gonna find diffrent way of doing it. –  10HeadLess Jun 8 '13 at 13:33
    
I'm currently thinking about a way of calculating b from a mod b = c I have a and c. I think that this would fit it, because if a would be equal 80 and c would be 22, then you would get: 80 mod i = 22, so 80 - i*[80/i] = 22, so 22-80 = -i*[80/i], so 58 = i*[80/i] –  10HeadLess Jun 8 '13 at 13:35
    
@10HeadLess, you iterate for the values of $y,$ such that $y\cdot \left[\frac{80}{y}\right]=58$ Clearly, $-58\le y \le 58$ Which programing language you follow? –  lab bhattacharjee Jun 8 '13 at 13:41
    
i am using java –  10HeadLess Jun 8 '13 at 13:44
    
void process() { for (int y = -100; y < 100; y++) { if (y != 0) { double floor = Math.floor(80 / y); if (y * (int) floor == 58) { System.out.println(y); } } } } –  lab bhattacharjee Jun 8 '13 at 13:47

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.