Have a sweet dream friends.

How many liters of 60% alcohol solution should be added to 40 liters of a 20% alcohol solution to make a 50% solution?

Nathan is an ecologist. he’s studying the effect of secondary consumers on primary consumers. his current research focuses on a population of blue jays and crows. they eat caterpillars and mice. if the number of blue jays increases, what are the likely effects on other populations? 1the number of crows will increase. 2the number of mice will decrease. 3the number of mice will remain the same. 4the number of caterpillars will decrease.

How was the sat? what type of questions for math, writing and reading. did anyone get a near perfect score and if so how long did it take to study. i am very stressed and want to get at least a 1450.