Equation - 9th grade (14y) - math problems
- Camel and water
84% of the camel's weight is water. After drinking, its weight increased to 832 kg and water accounted for 85% of its weight. How much did it weigh before drinking?
- The devils
The devils weighed in hell with Dorota. They found that Dorota and the two devils weigh 250 kg together and Dorota and the four devils weigh 426 kg. All the devils weigh the same. How Much Does Dorota Weigh?
- Geometric progressiob
If the sum of four consective terms of geometric progression is 80 and arithmetic mean of second and fourth term is 30 then find terms?
- Copper sulphate
How much g of water do we have to add to 240 g of an 84% CuSO4 solution to produce a 60% solution? (Express the mass of crystalline CuSO4 in the original solution and in the resulting solution and compare them. )
- The second
The second angle of a triangle is the same size as the first angle. The third angle is 12 degrees larger than the first angle. How large are the angles?
The price of the product was increased by 35%. How many percents of the new price we have to make it cheaper so that its price is equal to the original price?
- Trapezoid MO
The rectangular trapezoid ABCD with right angle at point B, |AC| = 12, |CD| = 8, diagonals are perpendicular to each other. Calculate the perimeter and area of the trapezoid.
Area of a square garden is 6/4 of triangle garden with sides 56 m, 35 m, and 35 m. How many meters of fencing need to fence a square garden?
If water flows into the pool by two inlets, fill the whole for 8 hours. The first inlet filled pool 6 hour longer than second. How long pool take to fill with two inlets separately?
Gross wage was 527 EUR including 16% bonus. How many EUR were bonuses?
- Right Δ
A right triangle has the length of one leg 7 cm and length of the hypotenuse 25 cm. Calculate the height of the triangle.
Route is long 147 km and the first day first regiment went at an average speed 12 km/h and journey back 21 km/h. The second day went second regiment same route at an average speed 22 km/h there and back. Which regiment will take route longer?
A man can drink a barrel of water for 26 days, woman for 48 days. How many days will a barrel last between them?
After three 10° beers consumed in a short time there are 5.6 g of alcohol in 6 kg adult human blood. How much is it per mille?
One meter of the textile were discounted by 2 USD. Now 9 m of textile cost as before 8 m. Calculate the old and new price of 1 m of the textile.
How many times a day hands on a clock overlap?
Calculate how many average minutes a year is the web server is unavailable, the availability is 99.99%.
- Chickens and rabbits
In the yard were chickens and rabbits. Together they had 54 heads and 118 legs. How many chickens and how many rabbits was in the yard?
Ladies sweater was twice discounted. First by 11%, then by 11% of the new price. Its final price was 100 €. Determine the original price of sweater.
- Short cut
Imagine that you are going to the friend. That path has a length 330 meters. Then turn left and go another 2000 meters and you are at a friend's. The question is how much the journey will be shorter if you go direct across the field?
Do you have a linear equation or system of equations and looking for its solution? Or do you have quadratic equation?