Natural numbers - 9th grade (14y) - practice problems
Number of problems found: 221
- Face combinations
If I have 20 sets of eyes, 20 noses, and 20 mouths, how many unique face combinations can I make?
- Multiple ratio
The numbers of boy students, girl students, teachers and other staff of the school are in the ratio 14: 12: 2: 1. How many teachers are there at school if there are 216 girl students at school?
- Even five-digit
How many even five-digit natural numbers with different digits can be created from the digits 0 - 6?
- Peter and Martin
Peter and Martin played by 67 balls. After the game, Peter had 9 more balls than Martin. How many balls did Martin win? Solve the help of the equation.
- The sum
The sum of two numbers is 69 and the difference is 11. Which numbers are they?
- Three dices
What is the probability that the sum of points 14 will be a roll of three dice (B, M, Z)?
- Find whole
Find whole numbers between 155 and 232 is divisible by 2, 5 and 10.
- Rabbits and chicken
There are rabbits and chicken at a farm, 41 heads and 132 legs in all. How many rabbits at the farm?
- Balls in row
Calculate the number of ways of placing 4 black balls, 4 turquoise balls and 5 gold balls in a row.
- Production plan
The annual production plan was exceeded by 2%. If production was higher by 300 products, the plan would be exceeded by 5%. What was the annual production plan?
- Children and horses
There are some children and horses in a field. Together they have 39 heads and 122 feet. How many children are in the field and how many horses are in the field?
- Perfect cube
Which of the following number is not a perfect cube? a. 64 b. 729 c. 800 d. 1331
- Two numbers
One number is by 79 larger than the other. If we divide the larger number by the smaller one, we get the ratio 5 and the remainder 11. Determine both numbers.
- The sum 16
The sum of A and B is 36. The difference between A & B is 8. find the larger number of A.
- Comparing exponents
A) 8 (6²)(8²) b) 16 (6²)(8²) c) (6¹+²) (8²)
- The sum 13
The sum of the exponents of the prime factors in the prime factorization of 196 is. .. .
- Three unknown numbers
The sum of of three numbers is 106. the first number is 10 more then the third. The second number is 2x the third. What are the numbers?
- The ratio 3
The ratio of male pupils to female pupils in Gymnasium is 7:9. If there are 512 pupils, how many pupils are male?
- Boys and girls 8
In a class of 35 boys and girls that has a ratio of 2:5, 5 boys are absent and 5 boys are present. How many students are present?
- Boys and girls
If the ratio of male & female teachers is 2/5 & it is in proportion of the male & female students, how many are girls if there are 42 boys?
Natural numbers - practice problems. Examples for 9th grade.