Answer:
There are 65,7 ml of acid.
Step-by-step explanation:
This is a percent problem. When we have a total (in this case 371 ml of a solution), it's value is the 100%. As only 17,7% is only the part we are interested in (acid), we shall get a cross-multiplication like this one:
371 ml ----------- 100%
x= ------------17.7%
This must be resolved multiplying 17.7 x 371 and dividing the result by 100.
![\frac{17,7 . 371}{100} = 65,667](https://tex.z-dn.net/?f=%5Cfrac%7B17%2C7%20.%20371%7D%7B100%7D%20%3D%2065%2C667)
This number rounded to the nearest tenth is 65,7.