Answer the following question.
Marla is mixing a particular shade of lilac that's 70% blue paint, 20% red paint, and the rest white paint. If she adds 140 ounces of blue paint, how many ounces of white paint does she add?
Step-by-step reasoning process: First find the total amount of paint Marla mixes by dividing the amount of blue paint by the percentage of the paint that's blue: 140 ounces / .7 = 200 ounces. Then multiply the total amount of paint by the percentage that's white to find the number of white ounces: 200 ounces * 10% = 20 ounces.
The answer is 20.

Answer the following question.
A mother planted a 16-inch tree on her son's first birthday. On the day the tree was planted, the boy was 24 inches tall. If the tree grows twice as fast as the boy does, how tall will the tree be by the time the boy is 36 inches tall?
Step-by-step reasoning process: The boy grew 36 - 24 = 12 inches since the tree was planted. Since the tree grows twice as fast as the boy, it will have grown 12 * 2 = 24 inches during this time period. Thus, the final height of the tree is 16 + 24 = 40 inches.
The answer is 40.

Answer the following question.
Tim hires two bodyguards. They each charge $20 an hour. He hires them for 8 hour per day. How much does he pay them in a week if he hires them 7 days a week?
Step-by-step reasoning process: It cost him 20 * 2 = $40 an hour for both of them. That means he pays 40 * 8 = $320 a day. So he pays 320 * 7 = $2240 a week.
The answer is 2240.

Answer the following question.
If a rectangle has a width of 42 inches and an area of 1638, how many rectangles of the same size would reach a length of 390 inches?
Step-by-step reasoning process: The rectangle has a length of 1638 in / 42in = 39 in. The number of rectangles required to reach 390 inches is 390 / 39 = 10 rectangles.
The answer is 10.