# Prime numbers + multiplication - math problems

#### Number of problems found: 31

• A number 5 A number is divisible by 24, 25, and 120 if it is increased by 20. Find the number.
• Two-digit number In a two-digit number, the number of tens is three greater than the number of units. If we multiply the original number by a number written in the same digits but in reverse order, we get product 3 478. Find the original number.
• Find unknown number What is the number between 50 and 55 that is divisible by 2,3,6,9?
• Prime divisors Find 2/3 of the sum's ratio and the product of all prime divisors of the number 120.
• Wedding guests Fifteen wedding guests could not agree on who would stand in the wedding photo. The groom suggested that all possible sets of wedding guests be made in the photographs.
• Prime factors Factor the number 6600 into the product of prime numbers.
• Twenty-five How many are three-digit natural numbers divisible by 25?
• The smallest number What is the smallest number that can be divided by both 5 and 7
• Inverted nine In the hotel Inverted Nine, each hotel room number is divisible by 6. How many rooms can we count with the three-digit number registered by digits 1,8,7,4,9?
• Dinosaurs More than 30 and less than 60 dinosaurs have met at the pond. A quarter of them bathed and 1/7 saws, and the rest gripped. How many were at the pond? How many were there?
• MO Z6-6-1 Write integers greater than 1 to the blanks in the following figure so that each darker box was a product of the numbers in the neighboring lighter boxes. What number is in the middlebox?
• Z7-I-4 stars 4949 Write instead of stars digits so the next write of product of the two numbers to be valid: ∗ ∗ ∗ · ∗ ∗ ∗ ∗ ∗ ∗ ∗ 4 9 4 9 ∗ ∗ ∗ ∗ ∗ ∗ 4 ∗ ∗
• Two friends Two friends met as a good man perish together for a beer. After recovery the most important topics (politics, women, football ...), one asks: - And how many do you have children? - I have 3 children. - And how many years have? Friend already not want to a
• Digits of age The product of the digits of Andrew age as 6 years ago and not equal to 0. Andrew's age is also the youngest possible age with these two conditions. After how many years will the product of the digits of Andrew age again the same as today?
• Four classses Students of all 7, 8 and 9 classes in one school may take up 4,5,6 and 7 abreast and nobody will left. How many is the average count of pupils in one class if there are always four classes each grade?
• Lcm 2 Create the smallest possible number that is divisible by numbers 5,8,9,4,3 On the meadow grazing horses, cows, and sheep, together with 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 equally. How many horses, cows, and sheep are on the meadow toget
• Lesson exercising The lesson of physical education, pupils are first divided into three groups so that each has the same number. The they redistributed, but into six groups. And again, it was the same number of children in each group. Finally they divided into nine equal g Grandson with grandpa, they counted how many years have together. Their product is 365. How many years is the sum of their years? How many different combinations of two-digit number divisible by 4 arises from the digits 3, 5 and 7?