Answer:
3.74%
Explanation:
We express a solution's volume by volume percent concentration, % v/v,
Take the ratio of the isopropyl alcohol (IPA) volume to the total volume of the solution, which is 1800 mL of water+ 70 mL of IPA,
and multiply by 100 to get the percentage: 70/(1800+70) *100 = 0.0374*100 = 3.74%