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?