# Examples for 8th grade - page 89

- Walnuts

x walnuts were in the mission. Dano took 1/4 of nuts Michael took 1/8 from the rest and John took 34 nuts. It stayed here 29 nuts. Determine the original number of nuts. - Two aircraft

From the airport will start simultaneously two planes, which fly tracks are perpendicular to each other. The first flying speed of 680 km/h and the second 840 km/h. Calculate how far the aircraft will fly for half an hour. - Way

If the current way to school was 2 km shorter then if Milan swipe one half he will have already one quarter of the way to school behind. How long is Milan's way to school? - Socks

One pair of socks worth CZK 27. Set of 3 pairs of these socks are sold with 10% discount. How many we will pay CZK for two offered sets of socks? - Regular n-gon

In a regular n-angle polygon the internal angle is 144 degrees. Find the number n indicating the number of sides of this polygon. - Stairway

Stairway has 20 steps. Each step has a length of 22 cm and a height of 15 cm. Calculate the length of the handrail of staircases if on the top and bottom exceeds 10 cm. - Tricolors

From the colors - red, blue, green, black and white, create all possible tricolors. - Efficiency

What is the power output of kettle 2 kW with efficiency 90%? - Working together on project

Two employees working on the project. First make it alone for 20 days the second for 24 days. How many days will take to complete project if 5 days they work together then first will take two days holiday and after returning they completes a project toget - Cylindrical tank

Cylindrical tank holds 600hl water and is deep 2.5 m. Calculate the diameter of the cylinder. - Volume increase

How many percent will increase in the pool 50 m, width 15m if the level rises from 1m to 150cm? - A mast

A mast 32 meters high was broken by the wind so that its top touches the ground 16 meters from the pole. The still standing part of the mast, the broken part and the ground form a rectangular triangle. At what height was the mast broken? - Cross section

The cross-section ABCD of a swimming pool is a trapezium. Its width AB=14 meters, depth at the shallow end is 1.5 meters and at the deep end is 8 meter. Find the area of the cross-section. - Cube 1-2-3

Calculate the volume and surface area of the cube ABCDEFGH if: a) /AB/ = 4 cm b) perimeter of wall ABCD is 22 cm c) the sum of the lengths of all edges of the cube is 30 cm. - Price increase

A 20 percent price increase meant a 90-crown raise. How many cost a product after? - Plane II

A plane flew 50 km on a bearing 63degrees20 and the flew on a bearing 153degrees20 for 140km. Find the distance between the starting point and the ending point - Adam and Ben

When Ben is so many years old to Adam today, Adam will be 23 years old. When Adam was as old as Ben, Ben was two years old. How old is today Ben and Adam? - Boys and girls

There are 48 children in the sports club, boys are 10 more than girls. How many girls go to the club? - Cargo

Car with cargo weight 7610 kg. Weight of car is 23% of the total weight of car and cargo. How heavy is cargo? - Rhombus MATH

Construct a rhombus M A T H with diagonal MT=4cm, angle MAT=120°

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