# Examples for 8th grade - page 14

- Climb

For horizontal distance 3 km road rise by 5.4 m. Calculate the road pitch in ‰ (permille, parts per thousand). - Double percent

What is 70% of 70% of 10500? - Unknown x

If we add to unknown number 72, then divide by 2 and then subtract 29, we get back an unknown number. What is this unknown number? - Train and car

The train and the car started at a constant speed to journey. When the train travels 78 km, the car travels 64 km. How many km travels the train when the car travels 78 km? - Class

In a class are 32 pupils. Of these are 8 boys. What percentage of girls are in the class? - Swimming pool 4

The pool shaped cuboid measuring 12.5 m × 640 cm at the bottom is 960hl water. To what height in meters reaches the water level? - Buses

Buses Ikarus and Karosa simultaneously started at 11:00 from the final station. Ikarus is returned to the station after 30 minutes. Karosa after 45 minutes. At what time both buses again returned to the station? - Gasholder

The gasholder has spherical shape with a diameter 23 m. How many m^{3}can hold in? - Waiting room

In the waiting room are people and flies. Together they have 15 heads and 50 legs (fly has 6 legs). How many people and flies are in the waiting room? - Hurry - rush

At an average speed 10 km/h I will come from the school to the bus stop for 29 minutes. How fast I need to go if I need to get to the bus stop in 21 minutes? - Pizza

A school survey found that 9 out of 16 students like pizza. If 5 students are chosen at random, what is the probability that all 5 students like pizza? - Five tractors

Five tractors plow field in 4.8 hours. How long plow this field if after 1.5 hours of work two tractors went to a different field? - Air

Room is 26.2 m long, 23.4 dm wide and 628 cm high. How many people can simultaneously be in this room if for hygiene reasons is calculated 5100 dm^{3}of air per person? - Square

Calculate area of the square with diagonal 70 cm. - Chess

How many ways can select 3 fields on classic chess board with 64 fields, so that fields don't has the same color? - Parachutists

Parachutists during freefall firstly held in groups of 4, then of 6, then 9, 12 and finally of 18 members. How many parachutists jump at least should be, if at each group must all be involved. - Arm

Calculate the length of the arm r of isosceles triangle ABC, with base |AB| = 16 cm and a height v=10 cm. - Ladislav in Amsterdam

Ladislav was reward and went to conference in Amsterdam. Conferense fee was € 2184. Calculate how many books Ladislav could buy at the price of 42 and 28 euros if he don't want fill whole home library and he can buy only 63 books? - Gloves

I have a box with two hundred pieces of gloves in total, split into ten parcels of twenty pieces, and I sell three parcels. What percent of the total amount I sold? - Apples 2

James has 13 apples. It has 30 percent more apples than Sam. How many apples has Sam?

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