To convert a percent to a decimal you divide by 100
1.6% = .016
You then multiply .016 times 75.20 which is 1.2032
3:34...............................
Answer:
54.5 
Step-by-step explanation:
divide it to one rectangle and two different triangles.
Rectangles area: (8+3)*4 = 44
triangle top: 4*3/2 = 6
triangle bottom: 3*3/2= 4.5
sum the all up: 44+6+4.5 = 54.5
don't know how to do it with π though if that's obligatory
3 gallons of acid = 100% concentration acid
? (water+acid) gallons = 15 concentration acid
Note: Every gallon of water added reduces the percentage concentration of acid. Therefore, the relationship is inverse proportionality.
Solution:
Total number of gallons (water+acid) = (3*100)/15 = 20 gallons
Therefore, gallons of water = 20-3 = 17 gallons