# Examples for 8th grade - page 13

- Diagonal in rectangle

In that rectangle ABCD is the center of BC point E and point F is center of CD. Prove that the lines AE and AF divide diagonal BD into three equal parts. - Solutions

How much 60% solution and how much 35% solution is needed to create 100 l of 40% solution? - Ladder

7.4 meters long ladder is leaning against the wall of the well and its lower end is 1.1 meters from this wall. How high from the bottom of a well is the top edge of the ladder? - 5 pumps

Five pump to pump 3 hours 1600 hl of water. How long pumped same amount of water 4 pumps? - Spherical cap

From the sphere of radius 12 was truncated spherical cap. Its height is 4. What part of the volume is spherical cap from whole sphere? - Rectangles

How many rectangles with area 2832 cm^{2}whose sides is natural numbers are? - Climb

For horizontal distance 3 km road rise by 5.4 m. Calculate the road pitch in ‰ (permille, parts per thousand). - Percent chaining

Calculate 20% from 70% from 80 km - Percent

From 117 children who participated in the ski course were 24 excellent skiers, 26 good and 26 average and the rest were beginners. Calculate this data in percentages. - Is equal

Is equal following terms? ? - Logik game

Letter game Logik is a two player game, which has the following rules: 1. The first player thinks five-letter word in which no letter is not repeated. 2. The second player writes a five-letter word. 3. The first player answers two numbers - the first numbe - Cars plates

How many different licence plates can country have, given that they use 3 letters followed by 4 digits? - Alcohol

How many 46% alcohol we need to pour into 3 liters 63% alcohol to get p3% of the alcohol? How many 52% alcohol we get? - Digging companies

Company A would dig a pit for 12 days, company B for 15 days, company C for 20 days and the company D for 24 days. Work began together companies C and D, but after three days joined them other two companies. How long took to dig a pit? - Cosine

The point (21, 20) is on the terminal side of angle θ. cos θ = ? - Gasholder

The gasholder has spherical shape with a diameter 23 m. How many m^{3}can hold in? - Prism

The lenght, width and height of a right prism are 18, 14 and 9 respectively. What is the lenght of the longest segment whose endpoints are vertices of the prism? - Pediatrician

Pediatrician this month of 21 working days takes 3 days holidays. What is the probability that on Monday will be at work? - Compass

What angle are between directions W (West) and SE (SouthEast) on the compass? - Tippler

Bottle with cork cost 9.9 Eur. The bottle is 0.9 euros more expensive than cork. How much is a bottle and the cork?

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