Maths practice for 14 year olds - page 380 of 382

Number of problems found: 7627

Two doctors
Doctor A makes the correct diagnosis with a probability of 89% and Doctor B with a probability of 75%. Calculate the probability of a correct diagnosis if both doctors examine the patient independently.
Monkey
The monkey fell into 20 meters deep well. Every day it climbs 3 meters, at night it drops back by 2 m. On what day it gets out from the well?
Clocks
How far does the tip of a clock's minute hand travel in 340 minutes if the minute hand is 23 cm long? How far does the tip of the hour hand travel in the same time?
Kites
Boys fly kites on cables 68 metres long. What is the altitude of a kite if the cable makes an angle of 72° with the horizontal?
Ladislav in Amsterdam
Larry was sent to a conference in Amsterdam as a reward. The conference fee was €1702. Calculate how many books Larry could buy at prices of 30 and 28 euros each, given that he does not want to fill his entire home library and may buy only 59 books in tot
Chess
How many ways can you select 4 fields on a classic chessboard with 64 fields so that fields don't have the same color?
Maximum area of rhombus
At what interior angles does a rhombus have the maximum area?
Road
Between cities A and B there is a route 9 km long with an average gradient of 9‰ klesanie. Calculate the height difference between cities A and B.
Angles in triangle
In a triangle, the ratio of angles β to γ is 6:8. Angle α is 40° greater than β. What are the sizes of the angles of the triangle?
Jewel
A rhombus-shaped jewel has an area of 23 mm² and a side length of 5.9 mm. Calculate the size of the acute angle of the rhombus.
Drunk man
The drunk man has 2.6‰ of alcohol in his blood. How many grams of alcohol has in his blood if he has 5 kg of blood?
Triangle SAS
Calculate the area and perimeter of a triangle if two sides are 46 m and 33 m long and the angle between them is 170°.
Circle chord
What is the length of a chord of a circle with diameter 115 m if the chord's distance from the centre is 11 m?
Circle in rhombus
A circle is inscribed in a rhombus. The points of tangency divide each side into segments of length 14 mm and 9 mm. Calculate the area of the circle.
Rectangle
The area of a rectangle is 893. Its length is 28 more than its width. What are the dimensions of the rectangle?
Square diagonal
Calculate the length of the diagonal of a square whose perimeter is 172 cm.
Hollow sphere
Calculate the weight of a hollow dural sphere (density 2.75 g/cm³) if the inner diameter is 18 cm and the wall thickness is 3 mm.
Salary
Operatér got to pay 2560 Euros in banknotes of 20 and 500 Eur. Total got 8 banknotes. How many were which?
Chickens and rabbits
In a farmyard there were chickens and rabbits. Together they had 30 heads and 100 legs. How many chickens and how many rabbits were in the yard?
Cube - angles
Calculate the angle alpha (α) between the face diagonal and the base of a cube. Calculate the angle beta (β) between the space diagonal and the base of the cube.

Do you have homework that you need help solving? Ask a question, and we will try to solve it. Solving math problems.