Solution for installing solar panels on inclined roofs

Question 1203015: How many liters of water must be added to 20 liters of a 20%salt solution to make it a 12.5 % salt solution Please i need a diagram and step by step solution.thnk you …

Question 1108519: A painter can paint a building in 15 days and a coworker can do the same job in 10 days. If the first painter starts and 3 days later the coworker joins in to help finish the job, …

Question 851665: Darius buys a bottle of a chemical solution that contains 70% alcohol. If the bottle contains 500 milliliters of solution, how many milliliters of alcohol are in the solution?

In this case, there is just one solution, and the system is called independent. Whenever you end up with something that involves one of the variables, such as x = 10, the system is …

SOLUTION: Five hockey pucks and three hockey sticks cost $23. Five hockey pucks and one hockey stick costs $20. How much does on hockey puck cost?

Solution A contains 10% acid, and Solution B contains 30% acid. He will mix the two solutions to make 10 liters of a third solution, Solution C, containing 25% acid.

SOLUTION: A certain preparation consists of liquids x, y, and z in the proportion 5:2:1. How many gallons of the preparation can be made from a stock of materials consisting of 25 gallons o

Question 588098: Find the pattern for the following series of numbers: 8, 5, 4, 9, 1, 7, 6, 3, 2, 0. Hints: This series problems looks just like a normal series problem, but it is different. You must …

Let x = the number of ml of 60% acid solution to be added to (300-x) ml of 30% acid solution to obtain 300 ml of 50% acid solution. Change the percentages to their decimal equivalents.

The first acid solution contains 25% acid, the second contains 35% and the third contains 75%. He wants to use all three solutions to obtain a mixture of 64 liters containing 55% acid, using 3 …