a solution is obtained by mixing 300g of 25 solution and 400g of 40 solution by mass

a solution is obtained by mixing 300g of 25 solution and 400g of 40 solution by mass

**Answer:** To find the resulting concentration of the solution after mixing, we can use the formula:

C = (m1C1 + m2C2) / (m1 + m2)

where:

C = resulting concentration

m1 = mass of first solution

C1 = concentration of first solution

m2 = mass of second solution

C2 = concentration of second solution

Plugging in the values given in the problem, we get:

C = (300g x 0.25 + 400g x 0.40) / (300g + 400g)

C = (75 + 160) / 700

C = 0.35 or 35%

Therefore, the resulting solution has a concentration of **35**%.