Examples for 8th grade - page 46
1180 crowns is divided into three people that A got 20% less than B and C by 15% more than B. How many got A,B and C?
- Container with water
The weight of a container with water is 2.48 kg. If the cast 75% water, the container with water has a weight of 0.98 kg. Determine the weight of the empty container. How much water was originally in the container?
- Triangle SSA
Construct a triangle ABC if |AB| = 5cm va = 3cm, CAB = 50 °. It is to create the analysis and construction steps.
How many CZK we pay for lining the perimeter walls of the bathroom with rectangular shape with dimensions 3.5 m and 4 m, high 1.5 m if 1 square m tile cost 300 CZK?
Suzanne helped write out diplomas. Issuance its first took 4 minutes, each next 2.4 minutes. How much time it will take to write out n=23 diplomas (including the first), write out this pace?
Buses Ikarus and Karosa simultaneously started at 11:00 from the final station. Ikarus is returned to the station after 30 minutes. Karosa after 45 minutes. At what time both buses again returned to the station?
- Water in aquarium
The aquarium cuboid shape with a length of 25 cm and a width of 30 cm is 9 liters of water. Calculate the areas which are wetted with water.
- Circle inscribed
Calculate the perimeter and area of a circle inscribed in a triangle measuring 3 , 4 and 5 cm.
- Distance runner
Distance runner already climbed three fifths of the total route. Thus passed 90 km. How many km he have to stop? How long is his route?
- Car consumption
The car has consumption 6.9 l/100 km. How much money will it cost ride 6.9 km in long if diesel price is 1.61 USD/l?
- Two workers
Two workers make 138 parts/items. The first one produces 30% more than the second. How many items will each produce?
The outer angle of the triangle ABC at the vertex A is 121°5'59″. The outer angle at the vertex B is 137°18'. What size is the internal angle at the vertex C?
- Great Wall of China
Great Wall of China is long 8880 km. Historically valuable however is only 30% of its length. What amount of insurance pays the Peoples Republic of China a month for this monument, if the insurance company charges $ 10 per year per kilometer of historic s
- Cars motion
From point A car start at the speed of 90 km/h. Against it departs from the point B at the same time another car at 60 km/h. For how long and where they met if the distance between A and B is 180 km?
First pump flows 16 liters per second into the basin by the second pump 75% of the first and by third pump half more than the second. How long will take fill basin by all three pumps simultaneously volume 15 m3 (cubic meters)?
Sum of interiol angles of 9-gon is:
- Complementary angles
Two angles are complementary. If one angle measures 49°, what is the measure of the second angle?
- Equation with fractions
Solve equation: ? It is equation with fractions.
Map scale is 1: 1000. The playground is rectangular and on the map has dimensions 10 cm and 5 cm What is area of playground in square meters in reality?
- Rectangle - sides 3
If in the rectangle ABCD we enlarge the side a by 5 cm and decrease the side b by 2 cm, the rectangle area will be reduced by 5 cm². When we decrease the length of the side a by 4 cm and and at the same time we increase the length of side b by 3 cm we incr