Help please for each of these

Liesl grew 7/12 of a foot in one year. her little sister grew 1/3 of a foot during that same year. how much more did liesl grow than her little sister did

Type the correct answer in each box. use numerals instead of words. the average number of subscribers to an online magazine each year from 2010 to 2015 is given in the table below. the average number of subscribers to the online magazine in 2010 was the percent increase in the average number of subscribers in 2011 to the average number of subscribers in 2012 was %. the maximum average number of subscribers to the online magazine in the years shown was

How many quarts of a 50% solution of acid must be added to 20 quarts of a 20% solution of acid in order to get a 40% solution of acid?