# The most difficult problems

#### Number of problems found: 6620

- Unknown mixed number

Find the number that is smaller than 5 5/12 by as much as 2 2/13 is smaller than 6 1/6 - Calculate 3

Calculate the cube volume whose edge is 3x-1,3x-1,3x-1 - Simplify

Simplify expression - which expression is equivalent to: 3(m + 2) − 4(2m − 9) - Rectangular field

A rectangular field has a diagonal of length 169m. If the length and width are in the ratio 12:5. Find the dimensions of the field, the perimeter of the field and the area of the field. - Three segments

The circle is divided into 3 segments. Segment A occupies 1/4 of the area. Segment B occupies 1/3 of the area. What part is occupied by section C? In what proportion are areas A: B: C? - Inquality

Solve inequality: 3x + 6 > 14 - One trapezium

One trapezium has AB=24M, BC=36M, CD=80M, DA=80M long sides. Find the area. - Infinite sum of areas

Above the height of the equilateral triangle ABC is constructed an equilateral triangle A1, B1, C1, of the height of the equilateral triangle built A2, B2, C2, and so on. The procedure is repeated continuously. What is the total sum of the areas of all tr - Iron density

Calculate the weight of a 2 m long rail pipe with an internal diameter of 10 cm and a wall thickness of 3 mm. The iron density is p = 7.8 g/cm^{3}. - Perfect cubes

Suppose a number is chosen at random from the set (0,1,2,3,. .. ,202). What is the probability that the number is a perfect cube? - Recipe

A recipe requires 2 pounds of flour. If a chef wants to triple the recipe, how many ounces of flour will be needed? - Flooring a room

Find the cost of flooring a room 6.5 m by 5 m with square tiles of sides 25 cm at the rate of rupees 9.40 per tile. - A tile

A tile setter is covering 5ft by 5ft square shower wall. Each tile covers 4 5/8in by 4 5/8in square. How many rows of tile are needed to reach 5ft? How many tiles are needed to cover 5ft by 5ft square - Area of a circle

The circumference of the circle is 150.72 centimeters. Calculate the area of the circle. - Find sales tax

What is 8.25% sales tax out of 1607.00? - Non linear eqs

Solve the system of non-linear equations: 3x^{2}-3x-y=-2 -6x^{2}-x-y=-7 - Std-deviation

Calculate standard deviation for file: 63,65,68,69,69,72,75,76,77,79,79,80,82,83,84,88,90 - A car

A car weighing 1.05 tonnes driving at the maximum allowed speed in the village (50 km/h) hit a solid concrete bulkhead. Calculate height would have to fall on the concrete surface to make the impact intensity the same as in the first case! - Bob traveled

Bob traveled 20 meters to Dave's house. He arrived in 3 minutes. What was his average speed for the trip. - The aquarium

The aquarium has a capacity of 18 liters. What is its height when the square bottom is 8 2/3 cm long?

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