A liter of one solution contains 20 g of salt, a liter of another solution is three times more.

A liter of one solution contains 20 g of salt, a liter of another solution is three times more. mixed 5 liters of the first solution and 3 liters of the second. How many grams of salt is in the new solution? How many grams of salt are there in 1 liter of new solution?

The number of grams of salt in one liter of the second solution will be equal to:
20 * 3 = 60 g.
The amount of salt in five liters of the 1st solution:
20 * 5 = 100 g.
And in three liters of the second:
60 * 3 = 180 g.
Then the total amount of salt in the new solution is:
100 + 180 = 280 g.
And one liter of a new solution contains:
280 / (3 + 5) = 280/8 = 35 g of salt.