# Examples for 7th grade (seventh) - page 68

1. Circle chord
Calculate the length of the chord of the circle with radius r = 10 cm, length of which is equal to the distance from the center of the circle.
2. Bakery and flour
The bakery tray for flour was filled to 3/4 volume. After removing 875 kg of flour, it was filled to only 2/5 of the volume. How many tons of flour is in the full tray?
3. Obtuse angle
Which obtuse angle is creating clocks at 17:00?
4. The rope
A 68 centimetre long rope is used to make a rhombus on the ground. The distance between a pair of opposite side corners is 16 centimetres what is the distance between the other two corners?
5. Alley
Alley measured a meters. At the beginning and end are planted poplar. How many we must plant poplars to get the distance between the poplars 15 meters?
6. Trees
A young tree is 16 inches tall. One year later, it is 20 inches tall. What is the percent increase in height?
7. Money split
Anton and Ferko got 2,500 euros together. The amount was split in 1:4 ratio. How much did each get?
8. Equation
Solve the equation: 1/2-2/8 = 1/10; Write the result as a decimal number.
9. MO Z8–I–6 2018
In the KLMN trapeze, KL has a 40 cm base and an MN of 16 cm. Point P lies on the KL line so that the NP segment divides the trapezoid into two parts with the same area. Find the length of the KP line.
10. Shirt
Mrs. Vítková bought each of his three children the same shirt paid CZK 1,000. Saleswoman she returned 568,60 CZK. What was the price of one shirt?
11. Pumps
After the floods, four equally powerful pumps exhausted water from the flooded cellar in 6 hours. How many hours would take a drained out with three equally powerful pumps?
12. Pills
If it takes 20 minutes to run a batch of 100 pills how many minutes would it take to run a batch of 50 pills
13. Three painters
The three painters have painted bridge. The first would work done in 5 days, the second in 6 days, and the third in 7.5 days. How long will the bridge work if they work together?
14. Magic number
The number 135 split to two addends so that one addend was 30 greater than 2/5 the addend.
15. Ratios
Reduce the numbers: 50 in a 1:2 ratio 111 at a ratio of 2:3 70 at 10:50 560 at a ratio of 3:8
16. Remainder
A is an arbitrary integer that gives remainder 1 in the division with 6. B is an arbitrary integer that gives remainder 2 the division by. What makes remainder in division by 3 product of numbers A x B ?
17. Thunder and lightning
There was a glimpse of the sky and we hear a thunder in 4.5 seconds. The light spreads at 300,000 kilometers per second, so we can assume the flash instantly without delay. However, the speed of the sound is much smaller in the air one third of a kilomete
18. Embankment
Perpendicular cross-section of the embankment around the lake has the shape of an isosceles trapezoid. Calculate the perpendicular cross-section, where bank is 4 m high the upper width is 7 m and the legs are 10 m long.
19. Unknown number 17
Milada said, I am thinking of a number such that I evaluate expression x1/3, the value of the expression would be 5. Which number Milada thinking?
20. Family 8
Father is 38 years old, daughter 12, son 14. How many years will father have as many years as his children together?

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