Answer:
The total weight is 80g, this is equal to the weight of the salt in the mixture plus the weight of the water in the mixture.
Ws = Weight of the salt
Ww = Weight of the water.
Then:
Ww + Ws = 80g
and the solution is 35% salt, so we have:
Ws/80g = 0.35
We must solve the system of equations, we can write the second equation as:
Ws = 80g*0.35 = 28g
Then we have 28 grams of salt, and the other 62g must be of water.