Examples for 8th grade - page 28
The elections attended a total 4436 voters. First day 32 men more than women, the second day 38 women more than men. How many women attended elections?
For the first week of material collection events are picked up at the school 850 kg of paper and 305 kg of rags which represented 55% of total collection for 14 days. How many kilograms of secondary raw materials were handed over totally?
- Painters 4
One painter will do the job for 12 days. After a 4 1/3 day he comes second to help him and complete work together for 8 days. How long would work the second painter himself?
Albert, Beny, Cyril and Dan worked on summerjob. From the total revenue Albert received 2/5, Beny 1/6 , 3/10 Cyril and Dan the rest which is 324 euros. How many euros earned every one of them?
- Equation with fractions
Solve equation: ? It is equation with fractions.
- Quadrant II
Calculate the radius of the quadrant, which area is equal to area of circle with radius r = 15 cm.
Convert to arc measures (radians): 1367 ° Result write as a multiple of π
We must dilute 80 liters of 7.6% aqueous vinegar to 4.2% one. How much water is necessary to add?
Cyclist started out of town at 20 km/h. After 0.6 hours car started behind him in the same direction and caught up with him for 52 minutes. How fast and how long went car from the city to caught cyclist?
- Gear wheels
Two gear wheels, which fit together have number of teeth z1=132 and z2=123. Calculate the speed of the first wheel, if the second wheel rotates 247 revolutions per minute.
The owner of the house is insured against natural disasters and pays 0.04% annually of the value of house 103 Eur. Calculate the value of the house. Calculate the probability of disaster, if you know that 42% of the insurance is to pay damages.
- Cone in cylinder
The cylinder is inscribed cone. Determine the ratio of the volume of cone and cylinder. The ratio express as a decimal number and as percentage.
- Cost reduction
Two MP3 players whose price was equal to originally have been discounted the first by 20%, the second by 35%. After the price reduction was the difference in their prices 750, - CZK. What was the original price of each of the two players?
A young tree is 16 inches tall. One year later, it is 20 inches tall. What is the percent increase in height?
- Four swords
Obelix has three helmets, four swords and five shields. How many swords must make at the blacksmith forge Metallurgix to be able to walk another 90 days in unique armor?
- Apples in baskets
Determine how many apples are in baskets when in the first basket are 4 apples, and in any other is 29 apples more than the previous, and we have eight baskets.
- Machines 2
2 machines for 50 hours produces 2,000 products. How many machines need to buy to make in 30 hours 15,000 products?
What percentage vinegar we get if we mix 1 if dm³ eight percent vinegar with 1.5 dm³ six percent vinegar?
- Inscribed triangle
To a circle is inscribed triangle so that the it's vertexes divide circle into 3 arcs. The length of the arcs are in the ratio 2:3:7. Determine the interior angles of a triangle.
800 pennies have the same value as 100 ducats. 100 pennies have the same value as 250 tolars. How many ducats has the same value as 100 tolars?