# Examples for 9th grade - page 51

- Water well

Drilled well has a depth 20 meters and 0.1 meters radius. How many liters of water can fit into the well? - Stamps and albums

Michail has in three albums stored 170 stamps. In the first album, there are 14 more than in the second and in the second is by 1/5 less than in the third. How many stamps are in the first album? - Crates 2

In 6 crates is 45 kg of apples In 5 crates is equally In 1 in crate is 3 kg more How many kilograms in each crate? - Double-track

On double-track express met with a freight train. Express travel at speed 72 km/h, a freight train at speed 36 km/h. After what time period will be from 9 km apart? - Annual income

The annual incomes (in thousands of $) of fifteen families is: 60, 80, 90, 96, 120, 150, 200, 360, 480, 520, 1060, 1200, 1450, 2500, 7200 Calculate harmonic and geometric mean. - High wall

I have a wall 2m high. I need a 15 degree angle (upward) to second wall 4 meters away. How high must the second wall? - Prism

Base of perpendicular triangular prism is a right triangle with cathetuses 4.5 cm and 6 cm. What is the surface of the prism, if its volume of 54 cubic centimeters. - Fraction

For what x expression ? equals zero? - Cleaners

Milan would clean up the room for 2.5 hours, Eric would take 10 hours. How long they swept the room together? - Bob and Bobek

At 10h 20min runs Bobek from hat at average speed 12 km/h. At what time must run out Bob at speed 18 km/h to catch him 9 kilometers from the hat? - Win in raffle

The raffle tickets were sold 200, 5 of which were winning. What is the probability that Peter, who bought one ticket will win? - Tower model

Tower height is 300 meters, weight 8000 tons. How high is the model of the tower weight 1 kg? (State the result in the centimeters). The model is made from exactly the same material as the original no numbers need to be rounded. The result is a three-digi - Reduce of the volume

Calculate how many % reduce the volume of the cube is we reduced length of each edge by 10%. - Powers

Express the expression ? as the n-th power of the base 7. - V - slope

The slope of the line whose equation is 8x +8 = 0 is - Statistics

The sum of all deviations from the arithmetic mean of the numerical sequence 1, 7, 7, 26, 43, 47, 80, 96, 113, 120 is: - Speedometer

The speedometer of a car reads 78 km/h. It's accurate to within 4.2% What is the maximum possible error? - Tiles

How much you will pay CZK for laying tiles in a square room with a diagonal of 8 m if 1 m^{2}cost CZK 420? - Chords

How many 6-tones chords (chord = at the same time sounding different tones) is possible to play within 10 tones? - 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?

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