How many grams of salt are needed to make 707 g of salt water that is 31.0% salt by mass?

Question

How many grams of salt are needed to make 707 g of salt water that is 31.0% salt by mass?

Answer 1

about 2281 grams

707/0.31 = about 2281 g

31% is about 30% = 3/10

707/3/10 = 707(10/3) = 7070/3 = about 2300. use a calculator for a better approximation of 2281