Themes, topics - practice problems

Number of problems found: 2575

A disease
A disease affects 10% of the individuals in a population and a sample of 100 peoples selected from the population. What is the probability of finding the disease in at least in at least 15 people?
Shortest 81627
What is the shortest distance across the globe's surface on a scale of 1:1,000,000 from the equator to the North Pole?
Energy 5
Energy is measured using the unit Joule (J). Temperature is measured using the unit degree Celsius °C). To increase the temperature of 1 liter of water by 1°C, 4200 J of heat energy is required. (a) Kelly wants to increase the temperature of 2 liters of w
Dimensions 81607
On a 1:150000 scale map, what will be the dimensions of a strip of the forest whose actual length is 6 km and actual width is 900 meters?
Probability 81591
We roll the dice three times. Calculate the probability of getting an even number on the first, second, or third toss.
Proportion 81558
Pour 9 dl of dye into 100 liters of water. What will be the proportion of dye in the resulting mixture? Express as a percentage.
Dinesh 2
Dinesh left town L for town M at a constant speed and took 10 hours to complete the journey. At the same time, Saanvi left town M for town L, traveled at a constant speed, and took 6 hours to complete the journey. They both passed each other at a point 72
Peter 16
Peter travels to his uncle's home, 30 km away from his place. He cycles for 2/3 of the journey before the cycle develops a mechanical problem, and he has to push it for the rest of the journey. If he is cycling 10 km per hour faster than his walking speed
Body's 81509
What was the body's mass when it moved along a path of 70 dm and did 1.4 kJ of work?
Resistance 81503
What is the value of the resistance of the rectifier diode in the forward direction if the current IF = 5 A flows through it and the voltage between the anode UF = 820 mV?
Satellite 81495
The satellite flies at a speed of 8 km/s. Will it fly down the runway in two seconds?
Map scale
On a map, on a scale of 1:50000, what is the distance in kilometers that 6 cm on the map represents?
Cheap chocolate
Lucy's chocolate bar is 29% cocoa. If the weight of the chocolate bar is 100 grams, how many grams of cocoa does it contain? Round your answer to the nearest tenth.
A statue
A statue on a shelf is recreated on a computer screen. The actual statue is 14 in. tall and 4 in. wide. The statue on the computer screen is 1.5 in. wide. How tall is the statue on the computer screen?
Intersection 81457
Two cars started from the right-angled intersection of two roads. The first at a speed of 80 km/h and the second at a speed of 60 km/h. How fast are they moving away from each other?
Square-shaped 81445
The area of the square-shaped room on the drawing with a scale of 1:150 is 6 cm square. Determine the actual area of the room in square meters.
Simultaneously 81441
The tank is filled through three openings, A, B, and C. The simultaneously open inlets A and B are filled in 1 hour, inlets A and C in 45 minutes, and inlets B and C in 1.5 hours. How long would it take to fill each inlet separately?
Evaporating 81430
Sea water contains 3.4% salt. How much salt do we get by evaporating 25 kg of seawater, and how much water evaporates?
Kilometers 81410
The tourist walked 1/4 of the way at a speed of 4.5 km/h, 2/5 at a speed of 4 km/h, and the remaining 7 km at a speed of 5 km/h. How many kilometers did he run, and how long did the journey take him? Calculate the time in a fraction.
Started 81404
At 7:30 AM, the bus left at a speed of 45 km/h, and at 8:00, a car behind it started at 65 km/h. Where and when did they meet?

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