Multiplication - 8th grade (13y) - examples
- 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 ∗ ∗
The root of the equation ? is: ?
How many different flags can be made from colors red, white, blue, black, yellow, green, purple, gray, orange so that each flag consisted of three different colors?
- Above 100%
What is 155% of 210?
How many ways can 7 guests sit down on 9 seats standing in a row?
How many ways are there to arrange 9 books on a shelf?
A man drinks a barrel of water for 31 days, woman for 58 days, for how many days they drink barrel together?
- Coin and die
Flip a coin and then roll a six-sided die. How many possible combinations are there?
- Drunk man
Drunkman has 2.1‰ of alcohol in the blood. How many grams of alcohol has in blood, if he have 6 kg of blood?
Write time in minutes rounded to one decimal place: 1 h 42 m 22 s.
Ladies sweater was twice discounted. First by 17%, then by 17% of the new price. Its final price was 72 USD. Determine the original price of sweater.
Gross wage was 1113 USD including 16% bonus. How many USD were bonuses?
The swimming pool is 6 m wide and 14 m long and 185 cm deep. How many hectoliters of water is in it, if the water is 9 cm below its upper edge.
- Compare II
Which of the numbers 158, 815 is greater?
The lorry was loaded with 27 boxes of 24 kg. How many boxes with weight 36 kg can be loaded, if total load must be same?
- Phone numbers
How many 9-digit telephone numbers can be compiled from the digits 0,1,2,..,8,9 that no digit is repeated?
- Friends in cinema
5 friends went to the cinema. How many possible ways can sit in a row, if one of them wants to sit in the middle and the remaining's place does not matter?
On the meadow grazing horses, cows and sheep, together 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 equall. How many horses, cows and sheep are on the meadow together?
- Daily average
Calculate the average temperature during the day, when 14 hours was 20 °C and 10 hours was 15 °C.
- Air mass
What is the weight of the air in a classroom with dimensions 5 m × 2 m × 3.1 m ? The air density is 1.293 kg/m3.