ID 614

  K8Captain Hook has two pieces of rope.
One piece of rope is 56 meters and the other is 98 meters.
He plans to cut the rope into pieces of equal length, with none left over.

What is the greatest possible length of each piece?



ID 671

  K8A tap drips one drop of water every second. It takes 3000 such drops to fill a 200-ml glass.

Estimate how much water was wasted in one day by this dripping tap?



ID 1203

  K8How many numbers between 77 and 177 are evenly divisible by 8 (no remainder)?



ID 1308

  K8Sebastian achieved these scores in his exams.

Which was his best result?



ID 1432

  K8Multiply all the digits of each license plate without using a calculator.

Find the plate with the largest total.



ID 1564

  K8On this target, I scored exactly 80.

How many shots did I fire?



ID 1655

  K8What number is greater than 9/10 and smaller than 10/11?



ID 1678

  K8Divide $1234 into the ratio 1:2:3:4.

What is the largest part of the ratio?



ID 1761

  K8This is a standard set of dominoes.
One domino has no spots, one domino has 1 spot, and two dominoes have 2 spots.
The greatest number of spots is 12.

Which number of spots appears more frequently on the dominoes?



ID 1779

  K8How many 2-digit integers are there in which the sum of the digits is equal to 5?



ID 1816

  K8In how many ways can you choose 4 of the first 8 positive integers so that no two integers are consecutive?



ID 1948

  K8Which number has the smallest number of divisors?



ID 2026

  K8A photographer will pay me $3600 per hour of taking a picture of my smile.

How much money will I receive for 1 second of the hard work?



ID 2943

  K8Which gives the largest answer?



ID 2970

  K821001 – 21000 – 2 x 2999 = ?



ID 2990

  K8Find the smallest positive integer that must be added to 2010 in order to obtain a number divisible by 9.



ID 3219

  K8If 144 is divided into three parts proportional to 7, 8 and 9, then the largest number is



ID 3319

  K8If you uniquely replace a, b, c and d with the numbers 0, 1, 2 and 3 , what is the largest possible sum of the fractions?



ID 3323

  K8Which point best represents the value of A divided by B?



ID 3324

  K8Which point best represents the value of C divided by F?



ID 3381

  K8How long is the golden chain with 10 links?



ID 3443

  K8What is the difference between sums of ten largest and ten smallest two-digit numbers?



ID 3508

  K8The number that is exactly halfway between 1/19 and 1/21 is



ID 3518

  K8A two-digit number, read from left to right, is 20% greater than the same number read from right to left.

What is the number?



ID 3544

  K8Three integer numbers yield the same answer whether they are added or multiplied together.
Find the largest of these three numbers.



ID 3618

  K8How many prime numbers end in 2 or 5?


A prime number is a natural number that has no positive divisors other than 1 and itself.



ID 3629

  K8In a list of five numbers, the product of the first three numbers, the last three numbers, and the three numbers in the middle is always 120.

What is the number in the middle?



ID 3768

  K8 The result of multiplying a number by 11 is the same as adding it to 11.

What is the number?



ID 3778

  K8Fill in each empty place between the numbers with one of the symbols +, -, x and /, with each symbol used exactly once.
No parentheses are allowed.

What is the least possible value of the result?



ID 3847

  K8What is 12.5 divided three times by 0.5 ?



ID 3868

  K8How many 5/9 pounds of potatoes are in a third of a pound?



ID 3905

  K8What is the difference between the sum of the first 99 even numbers and the sum of the first 99 odd numbers?



ID 3922

  K8What is the smallest positive integer that has 12 factors?



ID 3977

  K8Which is the smallest positive integer whose digits' product is 8000?



ID 4041

  K8If the average of a set of integers is 3 and their sum is 123, how many numbers are there?



ID 4092

  K8Which number is greater than the sum of its divisors other than 1 and the number itself?



ID 4102

  K8After how many kilometers will all the digits of the odometer be different for the first time?

Now it shows 78987 km.



ID 4271

  K8What is the sum of the cubes of the whole numbers from 1 to 5?



ID 4375

  K8Which number could not be written as a sum of 2 consecutive numbers?



ID 4466

  K8What is the smallest passcode that is evenly divisible by all of the numbers from 1 to 10?



ID 4536

  K8The number 2014 is the sum of a sequence of four consecutive integers.

Which of the numbers below occurs in the sequence?



ID 4622

  K8Which year comes midway between 1591 and 1951?



ID 4653

  K8An integer is even if it is evenly divisible by two.

A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself.

How many even prime numbers are there?



ID 4729

  K8Find the 4-digit number in which the second, third and fourth digits are twice the previous digit.

What is the sum of the digits?



ID 4787

  K8What is the product of the first five prime numbers?

A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself.



ID 4851

  K8What is 54321 less that the product of 30001 and 54321?



ID 5074

  K8What number added to itself three times is equal to 72?



ID 5086

  K8What is the sum of the first 9 numbers that are evenly divisible by 9?



ID 5161

  K8The opposite sides of a standard die have numbers that add up to seven.

I look at the tower of three dice from different directions and add up the number of all visible dots.

What is the sum?



ID 5198

  K8Which of these gives a nice shortcut to compute

11 x 99

in your head?



ID 5852

  K8Using the numbers 1, 2, 3, 4, and 5 in any order and operators plus (+), minus (-), times (x), and division (/) each exactly once, what is the greatest possible value that you can make?

Parentheses are not allowed.



ID 6065

  K8Which of the following numbers is closest to 33.33 × 44.44 ?
Do not use a calculator.



ID 6137

  K8If I want a ribbon that is a third of the size of this ribbon, at which point could I make a single vertical cut?



ID 6420

  K8What is the difference between 20172 and 20002 ?



ID 6534

  K8Put four operations signs between the numbers 1, 2, 3, 4, and 5 to make the largest possible result.

What will it be?

Don't change the order of the numbers, use all four signs, and don't use brackets.



ID 6542

  K8Which of the following is evenly divisible by 7 three times?



ID 6557

  K8Can you deduce what is going on here and therefore find out which digit should replace the question mark?



ID 6591

  K8If A, B, and C are different digits, what is their sum?



ID 6610

  K8Solve this in one minute without using calculators.

1997 x 1997 =



ID 6817

  K8How many integer numbers are greater than 2016 x 2018 and smaller than 2017 x 2017?



ID 7029

  K8Which number represents the largest amount?



ID 7077

  K8Multiply 43 by 57 in your head.



ID 7260

  K8What number multiplied by 3 is two-thirds of 333?



ID 7290

  K8How many zeros are there in ten billion?



ID 7309

  K8Which is the next number in the sequence?

1, 3, 6, 8, 11, 13, 16, …



ID 7322

  K8Leslie Green asks:

The product of three non-consecutive coprime integers is 70.

Which is the largest of the three?



ID 7350

  K8The product of two consecutive positive numbers is 156.

What is the largest number?