Reason - 9th grade (14y) - math problems
Number of problems found: 474
From the colors - red, blue, green, black and white, create all possible tricolors.
- Two-element combinations
Write all two-element combinations from elements a, b, c, d.
- Six on dice
What is the probability that when throwing two dice will fall at least one six?
How probable is a randomly selected three-digit number divisible by five or seven?
How many different ways can initiate a game of chess (first pass)?
- Diofant equation
250x + 120y = 5640
- One three
We throw two dice. What is the probability that max one three falls?
In how many points will intersect 14 different lines, where no two are parallel?
How many 19 element's subsets can be made from the 26 element set?
Solve algebrogram: mama+anna=vari How many solutions are?
- Consecutive numbers
Sum of ten consecutive numbers is 105. Determine these numbers (write first and last).
- Bookshelf and books
How many ways can we place 7 books in a bookshelf?
- The dice
What is the probability of events that if we throw a dice is rolled less than 6?
On coins found was stated that from the year 87 BC. It is right?
How many times must throw the dice, the probability of throwing at least one six was greater than 90%?
How many ways can 6 people sit on 6 numbered chairs (e. g. , seat reservation on the train)?
How many do three-digit natural numbers not have the number 7?
-12, 60, -300,1500 need next 2 numbers of pattern
Determine angles of the right triangle with the hypotenuse c and legs a, b, if: ?
- Hexagon = 8 parts
Divide the regular hexagon into eight equal parts.
Reason - math problems. Examples for 9th grade.