Carbon Dioxide: o2c
Water: h2o
Oxygen: o2
Water is h2o because there are 2 hydrogen molecules and 1 oxygen molecule.
h2 = 2 hydrogen molecules
o = 1 oxygen molecule
The answer would be C because they say if 3 new students arrived each year.
Ok, so 120 pages plus the 60% of the book she has left to read will give the total number of pages.
That means that 120 pages is 40% of the book.
Make a proportion
120/40% = x/60%
72 = .4 x
x = 180 pages
So x equals two if it is an exponent.9
