The multiplying bacteria

Algebra Level 1

In a glass there is a one bacteria. the bacteria multiplies itself by 2 each second, for example: 1,2,4,8,16. it takes the bacteria 60 seconds to multiply itself enough times to fill the glass. how many seconds does it take the bacteria to fill half of the glass.


The answer is 59.

Omer Ben-shaul by Omer Ben-shaul , 20, Israel

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

2 solutions

Omer Ben-shaul
May 23, 2014

since the bacteria doubles itself each second, it will take one second to get from half of the glass to the whole glass, so: 60 - 1 = 59

1 Helpful 0 Interesting 0 Brilliant 0 Confused

Realy brrilint question

Rubel Dey - 7 years ago
Pushan Paul
May 31, 2016

It is a geometric progression. The first term is a=1 and geometric ratio r=2. So after 60 seconds, ar^(n-1)=1 2(60-1)=2^59. Then half glass means 2^59/2=2^58. So, nth term is ar^(n-1)=2^58, 1 2^(n-1)=2^58, 2^n*2^-1=2^58, 2^n=2^59, n=59.

0 Helpful 0 Interesting 0 Brilliant 0 Confused

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...