Examples for 8th grade - page 59
How many square tiles with the content 121 cm2 has to be ordered for the paving of the square room with a side length of 2.75 meters?
- Chord 2
Point A has distance 13 cm from the center of the circle with radius r = 5 cm. Calculate the length of the chord connecting the points T1 and T2 of contact of tangents led from point A to the circle.
- Four classses
Students of all 7, 8 and 9 classes in one school may take up 4,5,6 and 7 abreast and nobody will left. How many is the average count of pupils in one class if there are always four classes each grade?
How much 60% solution and how much 35% solution is needed to create 100 l of 40% solution?
In the three-part tram went 109 passengers in front of others, 92 after others and in the middle half of all. How many passengers went in tram total?
Two boys started from one place. First went north at velocity 3 m/s and the second to the east with velocity 4 m/s. How far apart they are after minute?
- 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?
- Square garden
On the plan with a scale of 1:1500 is drawn as a square garden with area 4 cm2. How many meters is long garden fence? Determine the actual acreage gardens.
Diameter of motocycle wheel is 63 cm. How many times rotates wheel on roand long 1 km?
The ring made from gold and copper alloy has a weight of 14.5 g and a volume of 1.03 cm3. How much gold and how much copper it contains? The metal densities are Au 19.3 g/cm³ and Cu 8.94 kg·dm-3
- Plan scale
At what scale is drawn plan of the building, where one side of the building is 45 meters long is on the plan expressed by a straight line 12 mm long.
Sisters Janka and Danka are saved together 220 CZK. On a trip to Janka wants to take a fifth of her savings and Danka quarter. Then they will have 50 CZK on the trip. How much money saved Janka and Danka?
- Cutting circles
From the square 1 m side we have to cut the circles with a radius of 10 cm. How many discs we cut and how many percent will be waste?
- Earth's surface
The greater part of the earth's surface (r = 6371 km) is covered by oceans; their area is approximately 71% of the Earth's surface. What is the approximate area of the land?
- Three numbers
Find three numbers so that the second number is 4 times greater than the first and the third is lower by 5 than the second number. Their sum is 67.
- Mrs XY
Mrs Novak is employed. In January 2015 the gross income reached € 1193. Insurance is a 286.32 euros, and income taz 136 euros. Employer precipitated Mrs. Novak in recent clashes € 142, of which 64 euro for the savings account, and 78 euros for repayment of
- Borrowed book
Jane must as soon as possible return a borrowed book. She figured that when she read 15 pages a day return book in time. Then she read 18 pages a day and then return the book one day before. How many pages should have a book?
- New refrigerator
New refrigerator sells for 878 USD, Monday will be 25% discount. How much USD will save, and what will be the price?
- Square vs rectangle
Square and rectangle have the same area contents. The length of the rectangle is 9 greater and width 6 less than side of the square. Calculate the side of a square.
Determine the smallest integer p for which the equation 5 sin x = p has no solution.