# Math Help - [SOLVED] simple &amp; complicated calcul

1. ## [SOLVED] simple &amp; complicated calcul

Not sure.. :P just trying

20% of group young people says it's old = false
10% of old farts say their young = false

34% of total group (young + old) says they are old = While their is a 30% false in that group. So you take away 30% of the false of the actual old group and u calculate the amount of students by distracting the actual old group from 5000.

30% of 34% is 21%. 21% of 5000 = 1050 (actual old people) which leaves us 3950 students.

3. okay but its nice to try!

-- i've find 4300 lol --

okay but its nice to try!

-- i've find 4300 lol --
I assume you got the right answer? How did you get to that?

okay but its nice to try!

-- i've find 4300 lol --
I get 4000:

Let x be the number of young people. Therefore there are 5000 - x old people. Therefore:

$(0.2)x + (0.9)(5000 - x) = (0.34)(5000)$.