Equation - 7th grade (12y) - math problems

Floating of wood - Archimedes law
What will be the volume of the floating part of a wooden (balsa) block with a density of 200 kg/m3 and a volume of 0.02 m³ that floats in alcohol? (alcohol density is 789 kg/m3)
45th birthday
This year Mrs. Clever celebrated her 45th birthday. Her three children are now 7.11 and 15 years old. In how many years will Mrs. Clever's age be equal to the sum of her children's years?
Dividing money
Vilem, Cenek, and Edita divided the money they earned by spreading the leaflet. Vilem got 240 CZK more than Cenek and twice more than Edita. Edita got 400kc less than Vilem.
Radius of the circle
Calculate the radius of the circle whose length is 107 cm larger than its diameter
Garden
Area of a square garden is 6/4 of triangle garden with sides 56 m, 35 m, and 35 m. How many meters of fencing need to fence a square garden?
Forestry workers
In the forest is employed 56 laborers planting trees in nurseries. For 8 hour work day would end job in 37 days. After 16 days, 9 laborers go forth? How many days are needed to complete planting trees in nurseries by others, if they will work 10 hours a d
Bonus
Gross wage was 527 EUR including 16% bonus. How many EUR were bonuses?
Troops
The route is long 147 km and the first-day first regiment went at an average speed of 12 km/h and journey back 21 km/h. The second day went second regiment the same route at an average speed of 22 km/h there and back. Which regiment will take route longe
Motion problem
From Levíc to Košíc go car at speed 81 km/h. From Košíc to Levíc go another car at speed 69 km/h. How many minutes before the meeting will be cars 27 km away?
Excavation
Mr. Billy calculated that excavation for a water connection dig for 12 days. His friend would take 10 days. Billy worked 3 days alone. Then his friend came to help and started on the other end. On what day since the beginning of excavation they met?
Root
The root of the equation ? is: ?
Diophantus
We know little about this Greek mathematician from Alexandria, except that he lived around 3rd century A.D. Thanks to an admirer of his, who described his life by means of an algebraic riddle, we know at least something about his life. Diophantus's youth l
Coffee
In stock are three kinds of branded coffee prices: I. kind......248 Kč/kg II. kind......134 Kč/kg III. kind.....270 Kč/kg Mixing these three species in the ratio 10:7:7 create a mixture. What will be the price of 1100 grams of this mixture?
Motion
If you go at speed 3.7 km/h, you come to the station 42 minutes after leaving the train. If you go by bike to the station at speed 27 km/h, you come to the station 56 minutes before its departure. How far is the train station?
Store
One meter of the textile was discounted by 2 USD. Now 9 m of textile cost as before 8 m. Calculate the old and new price of 1 m of the textile.
Hands
The clock shows 12 hours. After how many minutes will angle between the hour and minute hand 90°? Consider the continuous movement of both hands hours.
Rectangular cuboid
The rectangular cuboid has a surface area 5334 cm², its dimensions are in the ratio 2:4:5. Find the volume of this rectangular cuboid.
Bus vs. train
Bus started from point A 10 minutes before the train started from the same place. The bus went an average speed of 49 km/h, train 77 km/h. To point B train and bus arrived simultaneously. Calculate time of train journey, if train and bus travelled the.
Inflation
What is better for people (employees)? ?
Right triangle Alef
The obvod of a right triangle is 84 cm, the hypotenuse is 37 cm long. Determine the lengths of the legs.