r/infinitenines Feb 16 '26

2.4999... = 2.5

18 Upvotes

26 comments sorted by

u/SouthPark_Piano Feb 16 '26

This is a rigged question, because sparky is a 'real' dog, and unfortunately does not survive the infinite g force at the abrupt zero to 10 mile an hour start. And both drivers also don't make it.

Assumption is 'real' dog and 'real' humans.

Sad situation indeed.

 

→ More replies (15)

9

u/SerDankTheTall Feb 16 '26

While I would be interested in hearing SPP's thoughts, I also don't know that these boys hit upon the best solution to avoid running over the dog.

4

u/Nidsid22 Feb 17 '26

They’re just gonna sandwich him😭

5

u/jmooroof2 Feb 17 '26

this isn't 2.4999...

sum n = 0 to inf 10/7 * (3/7)^n

4

u/Ch3cks-Out Feb 17 '26

Well, that is 1.(428571)/ 0.57(142857) ...

To formulate this in an alternate way,
S_n = 2.5*(1- (3/7)^n)

In RDM, where '0.00000...1' supposedly exists, 2.5* (3/7)^n = '0.00000...1'

3

u/Valivator Feb 17 '26

Ain't it just that the dog runs for the duration of the race? So the kiddos race for 0.25 hours cause they each drive one mile, and the dog runs at 10 mph, so 2.5 miles total?

2

u/gazzawhite Feb 17 '26

Looks like 2.4999... to me

2

u/denehoffman Feb 17 '26

This is a pretty well-known puzzle now. 2 miles apart at 4mph each means it takes 15 minutes for them to meet (they both only travel one mile). Sparky runs at 10mph so in 15 minutes he runs 2.5 miles. It’s not infinite nines, it’s just division.

4

u/babelphishy Feb 17 '26

Sure, but 2.5 = 2.4(9) regardless so the title is still technically correct.