Reason - examples - page 34
Seven classmates go every day for lunch. If they always come to the front in a different order, will be enough school year to take of all the possibilities?
- Express train
International express train drove from Kosice to Teplice. In the first 279 km, the track was repaired, and therefore it was moving at a speed of 10km/h less than it was scheduled to drive. The rest of the 465 km trip has increased the speed by 8 km/h than.
How many 19 element's subsets can be made from the 26 element set?
- Five pupils
Five pupils clean 30 chairs one hour before four pupils. How many chairs clean one pupil in 1 hour?
Dana confuses sweater and wool has a choice of seven colors. In how many ways she can choose from three colors to the sleeves?
The boys and girls in the class formed without the rest of the fives, 2 girls and 3 boys. There are 6 girls missing to create mixed pairs (1 boy and 1 girl). How many girls are in the classroom?
- In the orchard
In the orchard, they planted 25 apple trees, 20 pears, 15 plums and 40 marbles. A strong late frost, however, destroyed a fifth of all new trees. Unfortunately, it was all the trees of one kind of fruit. What is the probability that the plums have died out
- Dinning room
How many different combinations can we choose if there are 3 soups, 5 kinds of main dish and 2 desserts in the dining room?
Hanka cut the 20 cm long straws into three pieces each piece had a length in cm. Then, with these three pieces, she tried to make a triangle. a) What circuit has each of the triangles? b) How long can the longest side measure? c) How many different trian
A class has 20 students. The classroom consists of 20 desks, with 4 desks in each of 5 different rows. Amy, Bob, Chloe, and David are all friends, and would like to sit in the same row. How many possible seating arrangements are there such that Amy, Bob, C
12, 60, -300,1500 need next 2 numbers of pattern
There are 20 peaches in the pocket. 3 peaches are rotten. What is the probability that one of the randomly picked two peaches will be just one rotten?
How many different rectangles with sides integers (in mm) have a circumference exactly 1000 cm?
- Find two
Find two consecutive natural numbers whose product is 1 larger than their sum. Searched numbers expressed by a fraction whose numerator is the difference between these numbers and the denominator is their sum.
- Square into three rectangles
Divide the square with a side length of 12 cm into three rectangles with have the same circumference so that these circumferences are as small as possible.
At the summer camp, there are 41 chalets. Some rooms are 3-beds, some 4-beds. How many campers from 140 are living in 3-bed?
If 2*3 = 60 ; 3*4 = 120 and 4*5 = 200, what is 2*5?
Danka and Janka collect clothes. Danka had 9 more than Janka, so she gave her 7. Which now has more cloth and how many?
- Bridge cards
How many bridge hands are possible containing 4 spades,6 diamonds, 1 club, and 2 hearts?
- Clock's gears
In the clock machine, three gears fit together. The largest has 168 teeth, the middle 90 teeth, and the smallest 48 teeth. The middle wheel turns around its axis in 90 seconds. How many times during the day do all the gears meet in the starting position?