# 7th grade (12y) + natural numbers - examples

1. Monkey
Monkey fell in 23 meters deep well. Every day it climbs 3 meters, at night it dropped back by 2 m. On what day it gets out from the well?
2. Diophantus
We know little about this Greek mathematician from Alexandria, except that he lived around 3rd century A.D. Thanks to an admirer of his, who described his life by means of an algebraic riddle, we know at least something about his life. Diophantus's youth l
3. No. of divisors
How many different divisors has number ??
4. Numbers
Determine the number of all positive integers less than 4183444 if each is divisible by 29, 7, 17. What is its sum?
5. Camp
In the camp are children. 1/2 went on a trip, 1/4 went to bathe and 38 children remained in the room. How many children are in camp?
6. Birthdate
Jane on birthday brought 30 lollipops and 24 chewing gum for their friends. How many friends has, if everyone receives the same number of lollipops and chewing gums? How much chewing gum and lollipops got any friend?
7. Camel
Camel owner wants to get out of the city into oasis. He bought 3000 bananas, which wants to sell in oasis. However oasis from the city divided 1,000 kilometers of desert. Camel can carry at one time up to 1000 bananas, and for every kilometer traveled, ea
8. Plums
In the bowl are plums. How many would be there if we can divide it equally among 8, 10 and 11 children?
9. Chocolate
How many times should be broken chocolate consisting of 10 × 12 pieces to get the 120 parts?
10. Seedcake
Seedcake costs 44 cents. How many minimum seedcakes we must buy that we can pay in cash only whole euros?
11. LCM
What is the least common multiple of 36, 44, 21?
12. Rectangles
How many rectangles with area 3032 cm2 whose sides is natural numbers are?
13. Game room
Winner can took win in three types of jettons with value 3, 30 and 100 dollars. What is minimal value of win payable in this values of jettons?
14. Divisibility
Determine the smallest integer which divided 11 gives remainder 4 when divided 15 gives remainder 10 and when divided by 19 gives remainder 16.
15. Exhibition
The teacher paid for 280 Kč for 4.A students for admission to the exhibition. How many students were on the exhibition?
16. Count of roots
How many solutions has equation x. y = 7757 with two unknowns on the set of natural numbers?
17. Four pupils
Four pupils divided \$ 1485 so that the second received 50% less than the first, the third 1/2 less than a fourth and fourth \$ 154 less than the first. How much money had each of them?
18. Basements
In the first basement is more flies than the spiders, the second vice versa. Each basement had spiders and flies together 100 feet. Determine how many could be flies and spiders in the first and second basement. PS. We only need, when you write how many.
19. Elections
The elections attended a total 4818 voters. First day 39 men more than women, the second day 21 women more than men. How many women attended elections?
20. Divisibility
Determine all divisors of number 84.

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