1. There is 600g of 7% salt water. How many grams of salt does it take to increase the concentration of brine to 10%?

2. 400 kilograms of fruits with 90% water content are shipped from the fruit warehouse. A week later, it was found that the water content was reduced to 80%. What is the total weight of this batch of fruit now?

Second, training camp

1. There is 700g of 2.5% salt water. How many grams of water should be evaporated from it to make 3.5% salt water?

2. Add 4 kg of water to 10 kg of 35% brine. What is the concentration of salt water?

Grandpa has 50g 16% sugar water. (1) How many grams of water should I add to dilute it into 10% sugar water? (2) How many grams of sugar do you need to add to make it 30% sugar water?