Please help me with this ive been struggling on it for a while

Volume of cylinder with a radius of 8cm and height of 25 cm

Achemist has 200 ml of a 10% sucrose solution. she adds x ml of a 40% sucrose solution. the percent concentration, y, of the final mixture is given by the rational function: the chemist needs the concentration of the final mixture to be 30%. how many milliliters of the 40% solution should she add to the 10% solution to get this concentration?

Aboat costs 19200 and decreases in value by 12% per year. how much will it cost in 5 years