I'm embarrassed to ask this fundamental question among questions of particle filters but : my daughter just had this marked wrong on a test.
The teacher said the answer was 1/3 of 240 = 80.
On one level I understand this using fractions (80 * 3 = 240) -- and at another level, typing this into a calculator (since we don't have infinite numbers) yields 79.9999999992. Doing this using fractional math makes sense but that's only because 240 "cleanly" has 3 pieces -- but how does this work decimally when we can't have infinite numbers and have to round up (which to me seems more an approximation than 79.992)
Why is my daughter's answer wrong? Can't they both be correct at different levels of precision? Is one answer fundamentally the correct one and why?
I hope I have the gist of my question down and thanks in advance for your answers.