Equation + natural numbers - examples
- Examination 2
In an examination, a teacher awards 2 marks for every correct answer and subtract a mark for every wrong answer. If there are 20 questions and a child scored 25 marks how many correct answer did the child get?
- Brick weight
The brick weighs 2 kg and a half bricks. How much does one brick weigh?
Leslie bought 8 same chocolates for 16 Eur. How many euros will he pay for 25 chocolates?
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
After check of textbooks found that every 10-th textbook should be withdrawn. Together 58 textbooks were withdrawn. How many textbooks were in stock before withdrawn and how many after withdrawn?
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?
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
Seedcake costs 44 cents. How many minimum seedcakes we must buy that we can pay in cash only whole euros?
Nicol mistake when calculate in school. Instead of add number 20 subtract it. What is the difference between the result and the right result?
- Rectangle diagonals
It is given rectangle with area 24 cm2 a circumference 20 cm. The length of one side is 2 cm larger than length of second side. Calculate the length of the diagonal. Length and width are yet expressed in natural numbers.
Straight line passing through points A [-3; 22] and B [33; -2]. Determine the total number of points of the line which both coordinates are positive integers.
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.
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?
Siblings collect a 2-crowns and 5-crowns. Together have 80 coins with a total of value 310 crowns. How many saved two-crowns and how many five-crowns?
I threw three chicken for a handful of grains and I noticed that it eat in a ratio of 8:7:6 and two of them grabbed 156 grains. How many grains have fought that chicken?
- Unknown number
Samuel wrote unknown number. Then he had add 200000 to the number and the result multiply by three. When it calculated he was surprised, because the result would have received anyway, if write digit to the end of original number. Find unknown number.
Landlord had 49 ducats more than Jurošík. How many ducats Jurošík steal landlord if the Jurošík now 5 ducats more?
- Digits A, B, C
For the various digits A, B, C is true: the square root of the BC is equal to the A and sum B+C is equal to A. Calculate A + 2B + 3C. (BC is a two-digit number, not a product).
The sum and the product of three integers is 6. Write largest of them.
- CZK coins
Thaddeus and Jolana together have 15 CZK. Jolana has half of Thaddeus money. Nevertheless Jolana has 3 coins and Thaddeus 2 coins. Which coin has Thaddeus and Jolana (Help: CZK coins has values 1,2,5,10,20,50 CZK)?
Do you have a linear equation or system of equations and looking for its solution? Or do you have quadratic equation?