Prime numbers - 7th grade (12y) - math problems

Number of problems found: 152

Lcm = 22 + gcd
The least common multiple of two numbers is 22 more than their greatest common divisor. Find these numbers.
Athletics team
All athletes in the athletics team from Ostrava can start in four, five, six and seven stages, and no one will be present. How many average athletes are in one athletic group if there are a total of twelve groups in the section? Consider the smallest numb
Eights of butter
How many eights of butter (1/8 of kg = 125 g) can be stored in a box with dimensions of 4 dm, 2 dm, 1.8 dm, if the eighth of butter has dimensions of 8 cm, 5 cm, 3 cm?
A number 5
A number is divisible by 24, 25, and 120 if it is increased by 20. Find the number.
What fraction
What fraction of number 1 to 30 is prime?
The drama club
The drama club meets in the auditorium every 6 days and the choir meets there every 5 days. If the groups are both meeting in the auditorium today, then how many days from now will they next have to share the auditorium?
Mangoes
Chris has 12 mangoes and Jay has 18 mangoes. Each of them will share the mangoes to their friends . What's the greatest number of mangoes each of their friends get if Chris and Jay will give the same number of mangoes?
Part-time workers
On Saturday, 210 part-time workers arrived in the village. One hundred five part-time workers worked on the first field, 60 on the second. The other part-time workers worked in the third field. They all worked in equal groups. How many workers worked in e
A rope
A rope can be cut into equal length with no rope left over. The lengths can be 15cm,18cm or 25cm. What is the shortest possible length of the rope?
John Smith
John Smith is reading a 435-page novel. If he reads the same number of pages per day and the number is a prime number greater than 10, how many pages per day will he read?
Jordan
Jordan wants to bring in cookie cakes to share with his 23 classmates for his birthday. His mom is willing to buy no more than 6 cookie cakes and Jordan must share the cakes equally between his classmates (and himself). Answer the questions to help Jordan
Find unknown number
What is the number between 50 and 55 that is divisible by 2,3,6,9?
Two hundred
Two hundred ten athletes competed in three athletics races on three fields. One hundred five athletes competed in the first, 60 in the second, and everyone else in the third. On the individual courts, the athletes were divided into groups. Each group, alt
The classroom
The classroom is 9 meters long. The width of the classroom is smaller and can be passed in equally long steps of 55 CM or 70 CM. Determine the width of the classroom.
Square gardens
The gardening colony with dimensions of 180 m and 300 m is to be completely divided into equally large square areas with the largest possible area. Calculate how many such square areas can be obtained and determine the side length of the square.
Prime divisors
Find 2/3 of the sum's ratio and the product of all prime divisors of the number 120.
Summer camp
Some boys or girls signed up for the summer camp, which has a maximum capacity of 200 children. The main leader noticed that during the evening start, he could arrange the participants exactly in the twelve-step, sixteen-step, or eighteen-step, and no one
Tractor wheels
The front wheel of the tractor has a circumference of 18 dm and the rear 60 dm. We will make a red mark on the lowest point of both wheels. The tractor then starts. At what distance from the start will both marks appear identically at the bottom again?
Three
Three buses follow the same circular route. The first driver is the slowest because he has many stops, and it takes him 90 minutes to cross the route. The second driver will pass the circuit in 1 hour. The third driver has the fewest stops, and the circui
Pegs
From two sticks 240 cm and 210 cm long, it is necessary to cut the longest possible pegs for flowers so that no residues remain. How many pegs will it be?