Chapter 1 - Section 1.7 - Problem Solving: Interest, Mixture, Uniform Motion, Constant Rate Job Applications - 1.7 Asses Your Understanding - Page 142: 46

The number of oxygen atoms is 11, the number of carbon atoms is $12$ and the number of hydrogen atoms is $22$

Let the number of oxygen atoms be $x$, then the number of carbon atoms is $x+1$ and the number of hydrogen atoms is $2x$. Then our equation is $x+1+x+2x=45\\4x=44\\x=11$. Thus the number of oxygen atoms is 11, the number of carbon atoms is $12$ and the number of hydrogen atoms is $22$