Examples for 9th grade - page 3
How many different flags can be made from colors red, white, blue, black, yellow, green, purple, gray, orange so that each flag consisted of three different colors?
How many ways can 7 people sit on 3 numbered chairs (eg seat reservation on the train)?
- Football league
In the 2nd football league is 19 teams. How many ways can be filled first, second and third place?
How many ways can 7 guests sit down on 9 seats standing in a row?
In the box are 12 candies that look the same. Three of them are filled with nougat, five by nuts, four by cream. At least how many candies must Ivan choose to satisfy itself that the selection of two with the same filling? ?
- Stock market
Simon one day decided to invest € 88000 to the stock market. After six months he invested July 5 stock markets fell by 56%. Fortunately for Simon from July 5 5 to October 5 his shares have risen by 39%. Simon is then: ?
Trunk diameter is 72 cm. Is it possible to inscribe a square prism with side 54 cm?
Andrew wrote this series of numbers: 1,3,7,15, .... n. Which number in the series does not belong? ?
- Playing cards
How many possible ways are to shuffle 7 playing cards?
From complete sets of playing cards (32 cards) we pulled out one card. What is the probability of pulling the ace?
How many ways are there to arrange 9 books on a shelf?
Write the first 7 members of an arithmetic sequence: a1=8, d=-9.
A man drinks a barrel of water for 31 days, woman for 58 days, for how many days they drink barrel together?
Are diagonals in a rectangular trapezoid perpendicular and bisect the angles?
In how many ways can be divided gold, silver and bronze medal among 18 contestant?
Between cities A and B is route 3 km long of rise average 4‰. Calculate the height difference of cities A and B.
- Painter Pavel
Painter Pavel painted the fence for 20 hours and painter Petr the same fence painted for 17 h. How long should take painted the fence together?
- Amazing number
An amazing number is name for such even number, the decomposition product of prime numbers has exactly three not necessarily different factors and the sum of all its divisors is equal to twice that number. Find all amazing numbers.
- Right Δ
Right triangle has length of one leg 7 cm and length of the hypotenuse 25 cm. Calculate the height of the triangle.
In the trapezoid KLMN is given this informations: 1. segments KL and MN are parallel 2. segments KL and KM has same length 3. segments KN, NM and ML has same length. Determine the size of the angle KMN.