A contractor charges $ 200 for materials and $ 20 per hour for labour. The total cost of painting an office is $ 340. How many hours did it take the painter to paint the office?
First, we know that the contractor charges a flat rate of $200 for materials. This is charged no matter how many hours they work so we subtract this from the total cost: 340-200=$140 and are left with a total of $140. This remaining amount is the cost of hourly labor. To find the number of hours worked we will divide this amount by the wage per hour: $140/$20/hr. We can do long division to determine that 20 goes into 140 7 times. The $ units will cancel out and we will be left with units in hours. So, the contractor worked for 7 hours.
What are the differences between eukaryotic and prokaryotic cells?
There are two types of eukaryotic cells: Plant and animal cells. There is only one type of prokaryotic cell. The main difference between prokaryotic and eukaryotic cells is that eukaryotic have a nucleus and prokaryotic do not. Prokaryotic cells are smaller and eukaryotic cells are much more complex with many organelles, such as mitochondria and an endosplasmic reticulum. Eukaryotic cells reproduce through mitosis and prokaryotic cells reproduce through binary fission.
3(x+2)=12 solve for x.
According to the order of operations, we first need to distribute the 3 among the numbers in the parenthesis. So, we need to multiply 3 by x and by 2. This gives us: 3x+3(2)=12, or 3x+6=12. Next, we want to isolate x on one side since we are trying to solve for x. So we will subtract 6 from both sides. This gives us 3x+6-6=12-6, or 3x=6. Now, we want to get x completely alone. The 3 is multiplied by x, so to get it on the other side we need to divide both sides by 3. This gives us 3x/3=12/3, or x=4.