# Combinations

From how many elements we can create 990 combinations 2nd class without repeating?

**Result****Leave us a comment of this math problem and its solution (i.e. if it is still somewhat unclear...):**

**Showing 0 comments:**

**Be the first to comment!**

#### To solve this verbal math problem are needed these knowledge from mathematics:

## Next similar examples:

- 2nd class combinations

From how many elements you can create 4560 combinations of the second class? - Combinations

How many elements can form six times more combinations fourth class than combination of the second class? - Blocks

There are 9 interactive basic building blocks of an organization. How many two-blocks combinations are there? - Trinity

How many different triads can be selected from the group 43 students? - Theorem prove

We want to prove the sentence: If the natural number n is divisible by six, then n is divisible by three. From what assumption we started? - Division

Division has 18 members: 10 girls and 6 boys, 2 leaders. How many different patrols can be created, if one patrol is 2 boys, 3 girls and 1 leader? - Examination

The class is 21 students. How many ways can choose two to examination? - Chords

How many 4-tones chords (chord = at the same time sounding different tones) is possible to play within 7 tones? - Fish tank

A fish tank at a pet store has 8 zebra fish. In how many different ways can George choose 2 zebra fish to buy? - A student

A student is to answer 8 out of 10 questions on the exam. a) find the number n of ways the student can choose 8 out of 10 questions b) find n if the student must answer the first three questions c) How many if he must answer at least 4 of the first 5 que - Quadratic equation

Find the roots of the quadratic equation: 3x^{2}-4x + (-4) = 0. - Discriminant

Determine the discriminant of the equation: ? - Roots

Determine the quadratic equation absolute coefficient q, that the equation has a real double root and the root x calculate: ? - Calculation of CN

Calculate: ? - Equation

Equation ? has one root x_{1}= 8. Determine the coefficient b and the second root x_{2}. - Quadratic function 2

Which of the points belong function f:y= 2x^{2}- 3x + 1 : A(-2, 15) B (3,10) C (1,4) - Solve 3

Solve quadratic equation: (6n+1) (4n-1) = 3n^{2}