# Multiplication - examples - page 12

1. Unknown number 2
I think the number. When he reduces it four times, I'll get 11. What number am I thinking?
2. Salt
1 t of sea water contains 25 kg of salt. How many tons of seawater must be evaporated to obtain 2 q of salt?
3. 3 years savings
Simple interest - Tereza has deposited CZK 100,000 in the bank with an annual interest rate of 1.5%. Interest is added each year and left aside. How many CZK crowns will has total after 3 years?
4. 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 gr
5. 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?
6. Percentages
Expressed as a percentage:
7. 3 years
The company has increased the number of employees. In year 2005 compared to 2004 13% more, in 2006 18% more against the previous year, in year 2007 20% more compared to 2006. How many % increase in the number of employees in 3 years?
8. Percent chaining
Calculate 20% from 70% from 80 km
9. Operations
Sum of the numbers 1.01 and 3.35 multiply by the difference of numbers 6.69 and 1.39.
10. With bracket
Calculate (evaluate) simple mathematical expression with a negative numbers and a bracket: 13+15*5-2*(-6)
11. 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 an
12. Double percent
What is 30% of 80% of 3200?
13. The largest number
Find the largest integer such that: 1. No figures is not repeat, 2. multiplication of every two digits is odd, 3. addition all digits is odd.
14. Land cost
The land is worth 33295 CZK. 1st owner has 5/15, 2nd owner has 4/15, 3rd owner has 1/5 4th owner has 1/5. How much CZK each of them will receive?
15. Locomotive
Whole loaded train weighs 760 tons. It has twenty wagons, each carrying 20 tons of grain and empty weighs 10 tons. How much weight a locomotive?
16. Scalar dot product
Calculate u.v if |u| = 5, |v| = 2 and when angle between the vectors u, v is: a) 60° b) 45° c) 120°
17. Value
Determine the value of the following exspressions: a) (23-25)·(4-5) b) (97-123):(18+8)
18. Gain
Find the gain whenever the output power is 21x the input power.