Reason + multiplication - math problems
Number of problems found: 81
- The manufacturer
The manufacturer found that 3% of the plates produced had a malfunction. Of the compliant, 75% are first and 25% second. What is the probability of producing first and second class plates?
- Boys and girls
There are 20 boys and 10 girls in the class. How many different dance pairs can we make of them?
How many different ways can three people divide 7 pears and 5 apples?
3400 eggs sliced hens for February and March. We have to calculate how many hens can make 3400 eggs when one hen give 2 eggs a day for 59 days.
- Dinning room
How many different combinations can we choose if there are 3 soups, 5 kinds of main dish and 2 desserts in the dining room?
- Holidays with grandmam
We have packed three T-shirts - white, red, orange and five pants - blue, green, black, pink and yellow. How many days can we spend with the old mother if we put on a different combination of clothes every day?
- Bookshelf and books
How many ways can we place 7 books in a bookshelf?
- Pages counting
There are pages numbered from 2 to 104 in the book. How many digits have to be printed to number the pages?
If 2*3 = 60 ; 3*4 = 120 and 4*5 = 200, what is 2*5?
- Warmer weather
This morning it was -6 °C. What temperature did the thermometer show yesterday if it was three times warmer?
-12, 60, -300,1500 need next 2 numbers of pattern
- Associative law multiplication
In a warehouse, you obtain a 20% discount but you must pay a 15% sales tax. Which would you prefer to have calculated first: discount or tax? Explain. (result write as: 1 = first discount, 2 = first tax, 3 = no matter what first)
- Unknown number 16
My number's tens is three times more then ones My number's ones is twice the number of thousands and my number's hundreds is half the number of of tens. I have two ones. which number am I?
- Odd/even number
Pick any number. If that number is even, divide it by 2. If it's odd, multiply it by 3 and add 1. Now repeat the process with your new number. If you keep going, you'll eventually end up at 1. Every time. Prove. ..
- 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 ∗ ∗
- 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?
- Add symbols
Add marks (+, -, *, /, brackets) to fullfill equations 1 3 6 5 = 10 This is for the 4th grade of the primary school - with no negative numbers yet
- 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
- Foot in bus
It was 102 people on the bus. 28 girls had two dogs. A 11 girls had one dog. At the next stop seceded 5 dogs (even with their owners). They got two boys together with three dogs. The bus drove one driver. How many foot were in bus?
- 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 wa