Q3. In a class there are 11 boys and 19 girls.
The mean weight of all 30 children is 32.85 kg.
The mean weight of the 11 boys is 31.9 kg.
Work out the mean weight of the 19 girls.

Becca wants to mix fruit juice and soda to make a punch. she can buy fruit juice for $3 a gallon and soda for $4 a gallon. if she wants to make 28 gallons of punch at a cost of $3.25 a gallon, how many gallons of fruit juice and how many gallons of soda should she buy?