# Grade - examples - page 139

1. Pyramid Z8–I–6
Each brick of pyramid contains one number. Whenever possible, the number in each brick is lowest common multiple of two numbers of bricks lying directly above it. That number may be in the lowest brick? Determine all possibilities.
2. Clay
How many cubic centimeters of clay is in a pit of dimensions 4 m x 3 m x 3 m?
3. Diagonals of diamond
Find the area and circumference of the diamond ABCD with 15m and 11m diagonals.
4. Milk
Mum bought 16 cartons of milk. One carton of milk weight 0.925 kg. How many weight all purchase?
5. Shell of cylinder
Calculate the content of shell the 1.6 m height cylinder with a base radius of 0.4 m.
6. Isosceles trapezoid
Calculate the circumference and the contents of the isosceles trapezoid if you know the size of the bases is 8 and 12 cm and the size of the arms is 5 cm.
7. Mountain
Mountain has the elevation 7450 meters and in the morning is the middle portion thereof in the clouds. How many meters of height is in the sky if bellow the clouds is 2,000 meters and above clouds are two fifths of elevation of the mountain?
8. Cost reduction
Two MP3 players whose price was equal to originally have been discounted the first by 20%, the second by 35%. After the price reduction was the difference in their prices 750, - CZK. What was the original price of each of the two players?
9. Class
In 7.C clss are 10 girls and 20 boys. Yesterday was missing 20% of girls and 50% boys. What percentage of students missing?
10. How old
The student who asked how many years he answered: "After 10 years I will be twice as old than as I was four years ago. How old is student?
11. Parallelogram
In the parallelogram we know one internal angle 67°33`. Calculate the other internal angles.
12. Virus
We have a virus that lives one hour. Every half hour produce two child viruses. What will be the living population of the virus after 3.5 hours?
13. Rounding
The following numbers round to the thousandth:
14. Grandmother
Children's grandmother bought two identical toy cars and a doll. Total paid 492 Kč. The doll was 150 Kč. How much money cost 1 toy car?
15. Two numbers
The sum of the two numbers is 1. Find both numbers if you know that half of the first is equal to one seventh of the second number.
16. Rape
The agricultural cooperative harvested 525 ares of rape, of which received 5.6 tons of rape seeds. Calculate the yield per hectare of rape.
17. Is right triangle
Decide if the triangle XYZ is rectangular: x = 4 m, y = 6 m, z = 4 m
18. Cuboid edges in ratio
Cuboid edges lengths are in ratio 2:4:6. Calculate their lengths if you know that the cuboid volume is 24576 cm3.
19. Fuel mileage
You have 3/8 tank of fuel. Estimate fuel consumption @ 6mpg. Estimate speed @ 50mph. Your fuel tank holds 200 gals. Figure out fuel mileage.
20. Rabbits 3
Viju has 40 chickens and rabbits. If in all there are 90 legs. How many rabbits are there with Viju?

Do you have an interesting mathematical example that you can't solve it? Enter it, and we can try to solve it.

To this e-mail address, we will reply solution; solved examples are also published here. Please enter e-mail correctly and check whether you don't have a full mailbox.