# Grade - examples - page 147

1. Electricity consumption cost Last year Karol family reduced its electricity consumption by 31% compared to the previous year and paid CZK 2883 less. How many CZK is electricity last year and how many two year ago?
2. Class In a class are 32 pupils. Of these are 8 boys. What percentage of girls are in the class?
3. Bag Nelly found interesting point. An empty bag weighs 4 kg less than full. And empty bag is 5 times easier than full. How many kg weigh things in this bag?
4. Crocuses The garden grow daffodils, crocuses and roses. 1400 daffodils, crocuses is 462 more and roses is 156 more than crocuses. How many are all the flowers in the garden?
5. Cylinder In a 1-meter diameter cylinder is 1413 liters of water, which is 60% of the cylinder. Calculate the cylinder height in meters, do not write the units. The resulting value round and write as an integer.
6. Bicycle The bicycle pedal gear has 36 teeth, the rear gear wheel has 10 teeth. How many times turns rear wheel, when pedal wheel turns 120x?
7. Runner 2 Marian run 12 meters in 8 seconds. How far would Marian run for 70 seconds, if still run at the same pace?
8. Difference of two number The difference of two numbers is 20. They are positive integers greater than zero. The first number raised to one-half equals the second number. Determine the two numbers.
9. Friends James and Jaroslav are friends. Together they had 48 toy cars. But if John took 8 cars from Jaroslav, Jaroslav will be have 1.5 times more toy cars than James. How many toy cars had Jaroslav and James?
10. Biketrial Kamil was biketrial. Before hill he set the forward gear with 42 teeth and the back with 35 teeth. After how many exercises (rotation) of the front wheel both wheels reach the same position?
11. AP - simple Find the first ten members of the sequence if a11 = 132, d = 3.
12. Summer camp Out of the 180 students at a summer camp, 72 signed up for canoeing. There were 23 students who signed up for trekking, and 13 of those students also signed up for canoeing. Use a two-way table to organize the information and answer the following questio
13. Truck and car At 6h45min the truck started at a speed of 36 km/h. At 7h30m behind it a passenger car. Find the average speed of passenger car if it will catch truck 72 km away from the factory.
14. Inscribed sphere How many % of the volume of the cube whose edge is 6 meters long is a volume of a sphere inscribed in that cube?
15. Sawmill factory Peter works in the factory. The bus stop is 10 km from the factory. Therefore, always when the bus arrives for Peter, the driver leaves factory and takes him to work. They are coming at the saw exactly at 8:00. Today the bus arrived 11 minutes earlier and.
16. EQ2 Solve quadratic equation: ?
17. Area of ditch How great content area will have a section of trapezoidal ditch with a width of 1.6 meters above and below 0.57 meters? The depth of the ditch is 2.08 meters.
18. Workers Group of workers washing half of the windows of the building in two hours. How long will take half the workers wash all the windows of the building?
19. Outer contact of circles Construct a circle k1 (S1; 1.5 cm), k2 (S2; 2 cm), and K3 (S3; 2.5 cm) so that they are always two outer contact. Calculate the perimeter of the triangle S1S2S3.
20. Permutations without repetition From how many elements we can create 720 permutations without repetition?

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.