Math problems

EASY
1. What is the GCF of 72 and 90?
2. 15 is what % of 20?
3. If ¾ of a number is 450, what is 3/5 of the number?
4. One edge of a cube is 10 centimeters.  What is the sum of all the edges of the cube?
5. An angle is 95 degrees.  What is its supplement?
6. The length of a rectangle is 24 centimeters and its width is 15 centimeters.  What is its perimeter?
7. If 125% of a number is 150.  What is the number?
8. In a class, there are 8 girls for every 11 boys.  If there are 24 girls, how many boys are there?
9. What is the value of 4 x (15 - 3) + 18 ÷ 3?
10. Write 7 billion, 800 million in scientific notation.

AVERAGE
1. In a test, Connie missed six items and got 80%.  How many items were in the test?
2. What is 16% of 450?
3. What is the area of a 24.5-centimeter by 9.3-centimeter rectangle?
4. Norma practices her piano lessons 35 minutes a day.  How many hours does she practice in seven days?
5. I had enough money to spend P180.00 a day for 40 days.  If I reduce my expenses to P150.00 a day, how long will my money last?

DIFFICULT
1. A laborer can finish a job in 5 hours.  What part of it can he finish from 8:30 AM to 9:45 AM?
2. If a car covers 85 kilometers on 10-liter of gasoline, how many liters to the nearest liters will it use to cover 300 kilometers?
3. A vendor buys tilapia at P59.50/kg and sells at P17.00/kg.  How much will he gain if he sells 150 kg?
4. A square measures 8 ¾ cm on one side.  What is the perimeter of a rectangle formed by three squares placed side by side?
5. A circle has a radius of 7 centimeters.  How much bigger is the area of a circle which has a radius three times as that as the smaller circle?