Amount of instant tea = 24 ounces
Amount of green tea = 12 ounces
Caffeine in instant tea = 40 mg / 8 fl. oz. = 5 mg/fl.oz.
Caffeine in green tea = 25 mg /8 fl. oz. = 3.125 mg/fl.oz.
Caffeine in 24 ounces of instant tea = 5* 24 = 120 mg
Caffeine in 12 ounces of green tea = 3.125 * 12 = 37.5 mg
Total amount of the mixture = 24 + 12 =36 ounces
Total amount of caffeine in the mixture = 120 + 37.5 = 157.5 mg
Caffeine per ounce in the final mixture = 157.5 / 36 = 4.375 mg/ fl.oz
