# Problems for 6th grade (the sixth graders) - page 49

1. Water tank What is the height of the cuboid-shaped tank with the bottom dimensions of 80 cm and 50 cm if the 480 liters of water reaches 10 cm below the top?
2. Tilapia A fish vendor sells 5/7 kilos of tilapia for 73.50. If you will buy 2 1/7 kilos of tilapia, how much will it cost?
3. Dance group The dance group formed groups of 4, 5, and 6 members. Always one dancer remains. How many dancers were there in the whole group?
4. Equation 29 Solve next equation: 2 ( 2x + 3 ) = 8 ( 1 - x) -5 ( x -2 )
5. Trees in alley There are four trees in the alley between which the distances are 35m, 15m and 95m. Trees must be laid in the spaces so that the distance is the same and the maximum. How many trees will they put in and what will be the distance between them?
6. Area of rectangle How many times will increase the area of the rectangle, if we increase twice the length and at the same time we decrease the width by the half?
7. Expression plus minus Evaluate expression: (-1)2 . 12 – 6 : 3 + (-3) . (-2) + 22 – (-3) . 2
8. Mixed numbers Rewrite mixed numbers so the fractions have the same denominator: 5 1/5 - 2 2/3
9. 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?
10. Dort The cube-shaped cube box has the dimensions of 30 cm × 30 cm × 12 cm. How many CZK (Czech crowns) would cost be the biggest cake that would fit into the box when a 10 cm³ cake costs CZK 0.5? The cake has the same shape as the box.
11. Twins with friend The twins Danka and Janka went to the cinema with their friend Betka. Only six seats in the second row were available in the cinema. How many do they may sit, if the twins want to sit next to each other, Danka always to the right of Janka and Betka near on
12. Temperature increase If the temperature at 9:am is 50 degrees. What is the temperature at 5:00pm if the temperature increases 4 degrees Fahrenheit each hour?
13. Equation 15 Solve equation with variables on both sides:
14. Pamela Lara Pamela spends her salary of 3000 for food, clothing, recreation and savings, which are in the ratio of 48:20:15:37, respectively. How much does he spend for savings?
15. Tailor 5 A tailor uses 13/4m of cloth to stitch a skirt. How many metres of cloth is needed to stitch 16 skirts?
16. Decorative fence The rectangular garden is 57 m long and 42 m wide. Calculate how much m² it will reduce if it encloses with a 60 cm wide decorative fence.
17. Constant motion The car has undergone constant motion 120 km in 1 hour 30 minutes. Determine its average speed. Determine how long car drove in the first 20 minutes and 50 minutes from the start of the move.
18. Temperature adding At a weather centre, the temperature at midnight was -2 degree Celsius and by noon it had raised 4 degree Celsius. What is the new temperature?
19. Two thirds Find two-thirds of the number equal to two-thirds of 99
20. Negative in equation 2x + 3 + 7x = – 24, what is the value of x?

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