# Examples for 7th grade (seventh) - page 53

1. Jam
Jar with jam weighs 800 grams. Jam weighs three times as much as the empty glass. What is the weight of jam that is in the glass?
2. Unknown number 7
16% of the unknown number is by 21 less than unknown number itself. Determine the natural unknown number.
3. The percentages in practice
If every tenth apple on the tree is rotten it can be expressed by percentages: 10% of the apples on the tree is rotten. Tell percent using the following information: a. in June rained 6 days b, increase worker pay 500 euros to 50 euros c, grabbed 21 fro
4. Timeage
Seven times of my age is 8 less than the largest two-digit number. How old I am?
5. Sales of products
For 80 pieces of two quality products a total sales is 175 Eur. If the first quality product was sold for n EUR per piece (n natural number) and the second quality product after 2 EUR per piece. How many pieces of the first quality were sold?
6. 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.?
7. Performance
Same number of tickets sold for 15 CZK, 20 CZK, 30 CZK and 40 CZK a total of CZK 13,230 on theatre performance. How many tickets were sold for this performance?
8. 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.
9. Type of triangle
How do I find the triangle type if the angle ratio is 2:3:7 ?
10. Rhombus EFGH
Construct the rhombus EFGH where e = 6.7cm, height to side h: vh = 5cm
11. Ski tow
The ski club has 168 pupils and used lift with 60 seats, while students always follow the same sequence in filling seats. How many times while riding a ski lift skier sitting in the same seat as the first run?
12. Pipe cross section
The pipe has an outside diameter 1100 mm and the pipe wall is 100 mm thick. Calculate the cross section of this pipe.
13. Mr. Happy
Mr. Happy planted 36.6 meters square gardens grass; It's a third of the garden more than half of the garden. What is square area of this garden?
14. Dwarfs
Four dwarfs would prepare firewood for Snow White in580 minutes. After an hour and a half they recruit friends so that finished preparing the wood for 280 minutes. How many dwarfs they recruited?
15. Parking
120 vehicles parking on the morning. Pasenger car is charged 20 CZK, 50 CZK per bus. The guard collected for parking 2640 CZK in total. How many cars and how many buses stood in the parking?
16. Grass seeds
How many kg of grass seed is needed to be sowing a circular field with a diameter of 120 meters when the 1 m2 should be used 0.8 grams seeds?
17. Unknown number
Determine the unknown number that is equal to a quarter of the fifth of number, which is by 152 more than unknown number.
18. Even / odd numbers
a / Using variable n write two consecutive odd numbers. b / the sum of three consecutive odd numbers is 333. What are this numbers?
19. Apples 2
James has 13 apples. He has 30 percent more apples than Sam. How many apples has Sam?
20. Sales stores
The first sales store passed the 1/3 and the second 2/5 of the total amount of goods.In third store passed the 2/3 rest of the goods. The remaining 40 kg of goods put into fourth store. How many kilograms of goods pass to a third store?

Do you have an interesting mathematical example 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 e-mail correctly and check whether you don't have a full mailbox.