# Examples for 8th grade - page 81

1. Ace
The length of segment AB is 24 cm and the point M and N divided it into thirds. Calculate the circumference and area of this shape.
2. Profitability
The purchase price of goods is 13000, the sales price is the 20000. What is the profitability as a percentage?
3. Hydrostatic force
What hydrostatic force is applied to an area of 30 cm2 in water at a depth of 20 m? (Water density is 1000 kg/m3)
4. Three children
3 children eat 8 chocolates in 6 days. How many chocolates 6 children eat in 18 days?
5. Calf
The weight of the calf meat obtained is 65% of the total weight of live calves. What was the weight of a calf from which 285 kg of meat was obtained?
6. Circle r,D
Calculate the diameter and radius of the circle if it has length 52.45 cm.
7. Midpoints
Triangle ABC with sides a = 5 cm, b = 3 cm, c = 40mm has a midpoint of K, L, M. How many centimeters is long perimeter of parallelogram KBLM?
8. Kite
John a kite, which is diamond shaped. Its diagonals are 60 cm long and 90 cm long. Calculate: a) the diamond side b) how much paper John needs to make a kite if he needs paper on both sides and needs 5% of the paper for bending.
9. Metals
In the Hockey World Cup play eight teams, determine how many ways can they win gold, silver and bronze medals.
10. Wide field
The field is 203 meters wide 319 meter long, what is the greater length of the rope by which length and width can be measured and find the exact number of time.
11. Collection
John has collected half a bucket of raspberries in 45 minutes, Eva collects the whole bucket in an hour. How many minutes it would take to fill a bucket if the two children work together?
12. Euros
Peter, Jane and Thomas have together € 550. Tomas has 20 euros more than Jane, Peter € 150 less than Thomas. Determine how much has each of them.
13. Inequation
Solve the inequation: 5k - (7k - 1)≤ 2/5 . (5-k)-2
14. Ages
John, Teresa, Daniel and Paul have summary 56 years. Their ages are in a ratio of 1:2:5:6. Determine how many years have each of them.
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.
16. Family
Mom is 42 years old and her daughters 13 and 19. After how many years will mother as old as her daughter together?