Examples for 9th grade - page 17
At this point, the first skier lead 14 km before the second skier and travels at a constant speed 13 km/h. The second skier rides at 19 km/h. How long take him to catch up the first?
Mother and Kate together weigh 27 kg more than the father. Father weighs 8.4 kg more than mother. Father weight 35 kg more than Kate. Determine weights of father mother and Kate.
- Sea water
Seawater contains about 6.8% salt. How many dm3 of distilled water we must pour into 30 dm3 of sea water to get water with 1.9% salt?
- Count of triangles
Given a square ABCD and on each side 8 internal points. Determine the number of triangles with vertices at these points.
How high is the building that throws horizontal shadow 58.5 m long at angle 36°36'?
- Chocholate pyramid
How many chocolates are in the third shelf when at the 8th shelf are 41 chocolates in any other shelf is 7 chocolates more the previous shelf.
- Journey to grandma
Daniel traveled to grandma. He travel 100 km along. Halfway travel by train, one quarter by bus, one tenth by the bicycle and the rest travel by car. How many km travel km by car?
- Three-digit numbers
How many three-digit numbers are from the numbers 0 2 4 6 8 (with/without repetition)?
- The chord
Side of the triangle inscribed in a circle is a chord passing through circle center. What size are the internal angles of a triangle, if one of them is 40°?
- Cross-country competition
Cross-country competition was attended by 76% of pupils of class 9.B. Class consis of 16 boys, two of whom did not run and 4 girls did not run. How many girls go to class 9.B?
A team of colleagues done the work in 20 days. After adding 2 colleagues from the beginning the work was completed in 15 days. How many members has the colleague team?
Calculate height of the equilateral triangle if its perimeter is 54?
- 4s pyramid
Regular tetrahedral pyramid has a base edge a=6 and collaterally edge length b=15. What is its height?
Can umbrella 75 cm long fit into a box of fruit? The box has dimensions of 390 mm and 510 mm.
Shepherd tending the sheep. Tourists asked him how much they have. The shepherd said, "there are fewer than 500. If I them lined up in 4-row 3 remain. If in 5-row 4 remain. If in 6-row 5 remain. But I can form 7-row." How many sheep have herdsman?
- Hockey game
In the hockey game was made 6 goals. Czech played against Finland. Czechs won 4:2. In what order to fall goals? How many game sequence was possible during the game?
Small tractor wheel with a diameter of 60 cm must be rotated 8 times to overcome some pathway. How many times must turn the big tractor wheel with a radius 60 cm to overcome the same distance?
Determine the number of items when the count of variations of fourth class without repeating is 50 times larger than the count of variations of third class without repetition.
Man goes with a dog on a long walk 18 km from the house. Man is walking at speed 5.3 km/h and a dog that constantly running between house and man at 17.1 km/h. How many kilometers will run the dog when they reach their destination?
A cyclist is moving at 26 km/h and follow pedestrian who is walking at speed 7 km/h. Walker has an advantage 13 km. How long take cyclist to catch up with him?