Jamal needs to create a nitric acid solution which is less than 15% nitric acid. he begins with 12 fluid ounces of a 20% nitric acid solution in water and he adds 8 fluid ounces of water. does he need to add more water?

To find the solution,we can first the amount of nitric acid contained in his solution:

12×20%
=2.4 ounces

We can then find the percentage of nitric acid in his solution after adding 8 ounces of water:
=2.4/(12+8) ×100%
=2.4/20 ×100%
=12/100 x100%
=12%

As 12%<15%, he does not need to add more water.

Hope it helps!

Move the decimal behind it