3. How many grams of calcium nitrate needs to be added to 400 g of water to make a solution that is 12.5% by mass of Ca(NO3)2?

(40 points) i need some . an answer definition is appreciated as well.

What is 140% of 25? because i need

22. catie is starting a babysitting business. she spent $26 to make signs to advertise. she charges an initial fee of $5 and then $3 for each hour of service. write and solve an inequality to find the number of hours she will have to babysit to make a profit. interpret the solution.!