Question

Tomas bought a bottle of shampoo that held 10.5 fluid ounces.He uses 1/2 of the shampoo every time he washes his hair.How many ounces of the shampoo are left after he washes his hair 2 times?

Answer 1

Amount of shampoo in the bottle = 10.5 ounces or $10\frac{1}{2}=\frac{21}{2}$

Shampoo used in each wash = $\frac{1}{2}$

So after 1st wash shampoo left is =

$\frac{21}{2}-\frac{1}{2}=\frac{20}{2}=10$ ounces

Shampoo left after 2nd wash = $10-\frac{1}{2}=\frac{19}{2}$ ounces

or 9.5 ounces are left after washing the hair 2 times.