Amount of shampoo in the bottle = 10.5 ounces or [tex]10\frac{1}{2}=\frac{21}{2}[/tex]
Shampoo used in each wash = [tex]\frac{1}{2}[/tex]
So after 1st wash shampoo left is =
[tex]\frac{21}{2}-\frac{1}{2}=\frac{20}{2}=10[/tex] ounces
Shampoo left after 2nd wash = [tex]10-\frac{1}{2}=\frac{19}{2}[/tex] ounces
or 9.5 ounces are left after washing the hair 2 times.
