# Expression of a variable from the formula - 6th grade (11y) - math problems

1. Cube edges The sum of the lengths of the cube edges is 42 cm. Calculate the surface of the cube.
2. Unknown number 5 Daniel think an integer. When he change this number at a ratio of 2:5 he got number 2.8. Determine what number think Daniel.
3. Bus lines Buses connections are started from bus stop on its regular circuit as follows: No. 27 bus every 27 minutes and No.18 every half hour. What time started this two bus lines run if the bus stop met at 10:15 am.?
4. Euros Peter spent a quarter of his pocket saving. He has 9 euros now in his wallet . How many euros spent?
5. Quotient Find quotient before the bracket - the largest divisor 51 a + 34 b + 68 121y-99z-33
6. Cuboid - Vab Find the surface of the cuboid when its volume is 52.8 cubic centimeters, and the length of its two edges is 2 centimeters and 6 centimeters.
7. Cuboid surface Determine surface area of cuboid if its volume is 52.8 cm cubic and length of the two edges are 2 cm and 6 cm.
8. Car consumption The car has passed 988 kilometers and consumed 66 liters of petrol. What is the consumption per 100 kilometers?
9. On the farm On the farm were housed 70 heads of cattle with food supply for 180 days. After 60 days, 10 head of cattle sold, and for the next 30 days they sold 10 more. How many days is sufficient supply of feed for the remaining cattle?
10. The tourist The tourist came started from the hostel at an average speed of 5km/h. Half an hour later, the bicyclist started along the same route at a speed of 20km/h. How many minutes will a cyclist catch up and how many kilometers will he go?
11. Surface of cuboid Find the surface of the cuboid if its volume is 52.8 cm3 and the length of its two edges is 2 cm and 6 cm.
12. Two thirds Find two-thirds of the number equal to two-thirds of 99
13. Natural gas in kWh Gas consumption for 2017 was 11,301 kWh I paid 532 € How much 1 m3?
14. Cuboid Cuboid has a surface of 516 cm2. Side a = 6 cm and b = 12 cm. How long is the side c =?
15. Three pumps The water tank is emptied with the first pump in 6 hours, with the second pump in 2 hours. In order to be emptied in 1 hour, all three pumps had to be started at once. How long will take tank be emptied by only the third pump?
16. Third dimension Calculate the third dimension of the cuboid: a) V = 224 m3, a = 7 m, b = 4 m b) V = 216 dm3, a = 9 dm, c = 4 dm
17. Divide money 2 Ben and Dan had the same amount of money at the start. When Ben gave 300 to Dan, the ratio of Ben 's money to Dan's money became 2:3. How much money did each have at first?
18. Bicycle gears The toothed wheel on the bicycle pedal has 40 teeth, the wheel on the rear wheel has only 16 teeth. How many times does the rear wheel turn if the pedals rotate 50 times?
19. Isosceles triangle The circumference of the isosceles triangle is 32.5 dm. Base length is 153 cm. How long is the leg of this triangle?
20. Cube edge Determine the edges of the cube when the surface is equal to 37.5 cm square.

Do you have an interesting mathematical word problem that you can't solve it? Enter it, and we can try to solve it.

To this e-mail address, we will reply solution; solved examples are also published here. Please enter the e-mail correctly and check whether you don't have a full mailbox.

Please do not submit problems from current active competitions such as Mathematical Olympiad, correspondence seminars etc...