Examples for 7th grade (seventh)
Number of problems found: 2155
Jan is 13 years and Peter 21 years old. For how many years will their ages in the ratio of 7:9?
Two workers fulfill a certain task when working together for 5 days, the first if he worked himself done work in 13 days. How many days will do whole job a second worker?
- The cube
The cube has a surface of 600 cm2, what is its volume?
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?
- Field on plan
Plan has a scale of 1: 2500.Determine dimensions in centimeters which will have on plan field with a length of 310 meters and a width of 182.5 meters.
- Pumps 3
Two pumps of the same power fill the garden pool for 10 hours. How many of these pumps would have to use if we want to shorten the filling of the pool to four hours?
Peter has a long rope 2 4/5 meter. Martin has a rope 20 cm longer. What distance ropes achieved if the boys link ropes?
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?
- The professor's birthday
Professor of mathematics had 57 birthdays. The director congratulated him. The professor asked the director: "And how old are you?" The director replied: "I'm exactly twice as many years than you were when I was old as to you today." How old is the direct
Perpendicular pole high 8 m tall broke and its toe fell 2.7 m from the bottom of the pole. At what height above the ground pole broke?
Calculate span of the arc, which is part of a circle with diameter d = 20 m and its height is 6 m.
Rectangular square has side lengths 183 and 244 meters. How many meters will measure the path that leads straight diagonally from one corner to the other?
Workers works 5 days a week and has 21 days of vacation a year. Calculate how many days is out of work and express it as a percentage. Consider that a year has 52 weeks.
Plane shape has a maximum area 677 mm2. Calculate its perimeter if perimeter is the smallest possible.
- Bicycle wheel
A bicycle wheel has a diameter of 60 cm. Approximately how many times does the wheel rotate at 2.5 km long trip?
The weight of 17 bottles is 91.7 kg. What is the weight of 1 bottle?
5 of the same bread has the same weight as three bread and 4 kg of fruit. What weight has one bread?
- Perimeter of the circle
Calculate the perimeter of the circle in dm, whose radius equals the side of the square containing 0.49 dm2?
- Dd 2-digit numbers
Find all odd 2-digit natural numbers compiled from digits 1; 3; 4; 6; 8 if the digits are not repeated.
- Lcm simple
Find least common multiple of this two numbers: 140 175.