Answer
\(6\frac{9}{16}\) fluid ounces
Explanation
First, we are going to find the total amount of shampoo he used. We know from a our problem that he uses \(\frac{1}{16}\) of the shampoo every time he washes his hair and he washed his hair 6 times, so we just need to multiply the number of times (6) by the amount used every time (\(\frac{1}{16}\)) to find how much shampoo he used:
\(6*\frac{1}{16} =\frac{6}{16} =\frac{3}{8}\)
We know that he used \(\frac{3}{8}\) of the bottle of shampoo. Since the bottle of shampoo held 10.5 fluid ounces, we are going to multiply 10.5 fluid ounces by \(\frac{3}{8}\) to find how much fluid ounces he used:
\(10.5f.oz*\frac{3}{8} =3.9375f.oz\)
Now, to find the ounces of shampoo left, we just need to subtract the ounces used (3.9375 fluid ounces) by the initial fluid ounces in the bottle of shampoo (10.5 fluid ounces):
\(10.5f.oz-3.9375f.oz=6.5625f.oz\) or expressed as a mixed fraction: \(6\frac{9}{16} f.oz\)
We can conclude that there are \(6\frac{9}{16}\) fluid ounces of shampoo left after Tomas washed his hair 6 times.
