First let under 12 = u, over 12 = o, and adults = a. We can now write the equations:
2u + 3a + 3o = 174 4u + 2a = 122 a + o = 46
Because we know that a + o = 46, and 3a + 3o is in the first equation, we can multiply 46 by 3 to get what 3a + 3o equals. This makes 138. Now we can substitute 138 into the first equation to get 2u + 138 = 174 2u = 36 u = 18
Now that we know what u equals, we can substitute it in to the second equation to get: 4(18) + 2a = 122 72 + 2a = 122 2a = 50 a = $25
I hope this helps! Let me know if you have any questions :)
Dividing of cells a sample problems of geometric
progression. Given that the intial number of cells is 40, then it will double
every 20 minutes. Within 7 hours the cells will divide into w by 21 times. So the
number of cells after 7 hrs is 4,194,040 cells.
