Reason + multiplication - examples
- Math logic
There are 20 children in the group, each two children have a different name. Alena and John are among them. How many ways can we choose 8 children to be among the selected A) was John B) was John and Alena C) at least one was Alena, John D) maximum one w
- MO Z6-6-1
Write integers greater than 1 to the blanks in the following figure, so that each darker box was product of the numbers in the neighboring lighter boxes. What number is in the middle box?
One brick is 2 kg and half a brick heavy. What is the weight of one brick?
The root of the equation ? is: ?
4 chickens give 4 eggs in 4 days. How many eggs can give 8 chickens for 8 days?
How many ways can 7 people sit on 3 numbered chairs (eg seat reservation on the train)?
- School trip
School trip cost 340.8 USD for one class (24 students). How much would cost a trip for two classes? (both classes together have 44 students)
In human body the blood is about 7.7% body weight. How many kilograms of blood is in the human body with weight 96 kg?
A man drinks a barrel of water for 31 days, woman for 58 days, for how many days they drink barrel together?
You want to cut long board into smaller pieces. Carpenter said that one cut of the board into two pieces will cost you 90 cents. But you need to cut the board into 7 parts. How much you pay?
Two cats caught two mice in two days. How many mouses will catch 6 cats for 6 days?
- Forest ranger
Forest ranger watching from the hide deers. At one time point he can see 6 deers. How many maximum deers can be see by 3 rangers at same time?
Grower harvested 190 kg of apples. Pears harvested 10 times less. a) How many kg pears harvested? b) How many apples and pears harvested? c) How many kg harvested pears less than apples?
How many times should be broken chocolate consisting of 7 × 10 pieces to get the 70 parts?
Gross wage was 1113 USD including 16% bonus. How many USD were bonuses?
In the market have 3 kinds of chocolates. How many ways can we buy 13 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
- Phone numbers
How many 9-digit telephone numbers can be compiled from the digits 0,1,2,..,8,9 that no digit is repeated?
On the meadow grazing horses, cows and sheep, together less than 200. If cows were 45 times more, horses 60 times more and sheep 35 times more than there are now, their numbers would equall. How many horses, cows and sheep are on the meadow together?
- Three digits number
How many are three-digit integers such that in they no digit repeats?