# Arithmetic - math word problems

1. Opposite numbers Calculate opposite numbers (additive inverse) to given ones:
2. Weight of air What is the weight of air in the living room measuring width 5 m length 2 m and height 2.8 m? Air density is ρ = 1.2 kg/m3.
3. CDs Adam has 6 CDs more than Filip and 7 CDs less than Dominica. Filip has 6 CDs. How many CDs has Adam and how many CDs has Dominika?
4. Rectangle A2dim Calculate the side of the rectangle, if you know that its area is of 2590 m2 and one side is 74 m.
5. Tank In the middle of a cylindrical tank with a bottom diameter 251 cm is standing rod which is 13 cm above the water surface. If we bank rod its end reach surface of the water just by the tank wall. How deep is the tank?
6. School books At the beginning of the school year, the teacher distributed 480 workbooks and 220 textbooks. How many pupils could have the most in the classroom?
7. Grower Grower harvested 190 kg of apples. Pears harvested 10 times less. a) How many kg pears harvested? b) How many apples and pears harvested? c) How many kg harvested pears less than apples?
8. Pairs From the five girls and four boys teachers have to choose one pair of boy and girl. A) How many such pairs of (M + F)? B) How many pairs where only boys (M + M)? C) How many are all possible pairs?
9. Root Use law of square roots roots: ?
10. Events Event P has probability of 0.84. What is the probability that the event P occurs in 3, 5, 7 try.
11. Shots 5500 lead shots with diameter 4 mm is decanted into a ball. What is it diameter?
12. Count of roots How many solutions has equation x. y = 7757 with two unknowns on the set of natural numbers?
13. Sphere growth How many times grow volume of sphere if diameter rises 10×?
14. 9.A 9.A to attend more than 20 students but fewer than 40 students. A third of the pupils wrote a math test to mark 1, the sixth to mark 2, the ninth to mark 3. No one gets mark 4. How many students of class 9.A wrote a test to mark 5?
15. Circles Area of circle inscribed in a square is 14. What is the area of a circle circumscribed around a square?
16. Tiles The room has dimensions 12 m and 5.6 m. Determine the number of square tiles and their largest possible size to cover them room's floor.
17. Insurance The owner of the house is insured against natural disasters and pays 0.04% annually of the value of house 77 Eur. Calculate the value of the house. Calculate the probability of disaster, if you know that 48% of the insurance is to pay damages.
18. Rectangle Area of rectangle is 3002. Its length is 41 larger than the width. What are the dimensions of the rectangle?
19. Equilateral cylinder Equilateral cylinder (height = base diameter; h = 2r) has a volume of V = 199 cm3 . Calculate the surface area of the cylinder.
20. Bits, bytes Calculate how many different numbers can be encoded in 16-bit binary word?

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