Math practice for 13 year olds - page 347 of 351
Number of problems found: 7012
- Proof I
When added to the product of two consecutive integers larger one, we get the square larger one. Is this true or not? - Energy saving
They released three different independent inventions saving 15%, 17%, and 16% energy. Some considered that with the use of these inventions, the total savings would be 15% + 17% + 16% = 48%. Is this true? How much will the percent of energy save all three - Median
In the right triangle are sides a=96 dm b=31 dm. Calculate the length of the medians tc to the hypotenuse. - Secret number
Find the secret number n, which reversed decreases by 16.4 if the number increases by 16.4.
- Seedcake
Seedcake costs 44 cents. How many minimum seedcakes must we buy that we can pay in cash, only whole euros? - Conserving water
Calculate how many euros are spent annually on unnecessary domestic hot water, which cools during the night in the pipeline. The residential house has 129 m of hot water pipelines 5/8" and the hot water has a price of 7 Eur/m³. - Triangle
Calculate the triangle's heights ABC if the triangle's sides are a=26, b=81, and c=73. - Lead cube
Calculate the cube's edge made from lead, which weighs 19 kg. The density of lead is 11341 kg/m³. - Pump
What power does a pump output to move 1060 hl of water to a height of 43 m for 8 hours?
- Chord MN
Chord MN of the circle has distance from the center circle S 120 cm. Angle MSN is 64°. Determine the radius of the circle. - Event probability
The probability of event N in 5 independent experiments is 0.4. What is the probability that the event N occurs in one experiment (chance is the same)? - Flags
How many different flags can be made from green, white, blue, red, orange, yellow, and purple materials, so each flag consists of three different colors? - Isosceles right triangle
Calculate the area of an isosceles right triangle whose perimeter is 810 cm. - Barrel of oil
The barrel of oil weighs 283 kg. When it molded 26% oil, it weighed 216 kg. What is the mass of the empty barrel?
- Concrete pipe
The concrete pipe is cylindrical, with an inner diameter of 60 cm and an outer diameter of 67 cm. If it is 10 m long, calculate its surface. - Extreme temperatures
The USA hit an extreme heat wave. Calculate the percentage of the air temperature change from normal summer temperature 23 °C to 40 °C. - Magnification of the square
If we increase the square side, increase the area of the 57 %. About what percentage was increased on its side? - The cyclist
The cyclist went from village to town. The first half of the journey went at 24 km/h. The second half of the journey, which mostly fell, went at 38 km/h. All journeys took 94 minutes. Calculate the distance from the village to the town. - Widescreen monitor
A wave of widescreen monitors and televisions hit computer businesses. Calculate the area of the LCD monitor with a diagonal size 27 inches at a ratio of 4:3 and then a 16:9 aspect ratio. Is buying widescreen monitors with the same diagonal more advanta
Cylinder with base radius r = 24 cm and height h=62 cm. Calculate: a) Area of the baseDo you have unsolved problem that you need help? Ask a question, and we will try to solve it. Solving math problems.
