4. Which formula describes the variation, “ v varies directly as t and inversely as w”?

6. Which of the following equations describes a combined variation, where k is the constant of variation?

7. What is the constant of variation in the equation, y = 10x ?

8. What happened to D ,when R is doubled in the equation, D = 5R ?

9. Which is an example of direct variation ?

10. Which variation is described in the sentence,” A car travels a distance d km in t hr ” ?

11. What is the constant of variation, if y varies directly as x and y = 32, when x = 4?

12. Which of the following table of data describes an inverse variation ?

13. What happens to T when h is doubled in the equation, T = dh ?

14. What happens to y when x is tripled in the relation, y = k/x ?

15. If y varies directly as x and y = 12 when x = 4, what is y when x = 12 ?

16. If y varies inversely as x and y = when x = 8, what is y when x = -4?

17. If s varies directly as t and inversely as v, then which of the following equations describes the relation among the three variables s, t, and v?

18. If (x-4) varies inversely as (y+3) and x = 8 when y = 2, what is x when y = -1?

19. w varies directly as the square of x and inversely as p and q. If w = 12, when x = 4, p = 2 and q = 20, what is w when x = 3, p = 8 and q = 5 ?

20. If 3 men can do a portion of a job in 8 days, how many men can do the same job in 6 days?

21. If y varies inversely as x, and y = 1/5 when x = 9, what is y when x = -3 ?

22. Khenz income varies directly as the number of days that he works. If he earns PhP 8,000 in 20 days, how much will he earn if he worked 3 times as long?

23. The amount of gasoline used by a car varies jointly as the distance traveled and the square root of the speed. Suppose a car used 25 liters on a 100 km trip at 100 kph, about how many liters will it use on a 1000 km trip at 64 kph ?

24. If y varies directly as the square of x, how is y changed if x is increased by 20%?

25.The distance Nika travels is directly proportional to the time she spends on the road. If Nika spends 5 hours on the road, she travels 30 miles. How far will she go if she only spends 3 hours on the road?

26. Which of the following equations represents the relation, “ speed r of a moving object is inversely proportional to the time t travelled”?

27. If y varies directly as x and y = 4 when x = 10, what is y when x = 15 ?

28. A newspaper boy earns Php 80 in 2 weeks. How much does he earn in 5 weeks if he sells at the same rate?

29. Mrs. Sanchez gives 15 points for every kilo of plastic bottles a student in her Science class submits. How many kilograms of plastic bottles must a student submit if he/she wants to get 60 points?

30. Which of these equations is a combined variation? 

31. What variation is illustrated by the relationship between ”the speed of a car to the time it takes the car to reach its destination”?

32. Which is the equation for the following relation, “the volume of a cylinder varies jointly as h and the square of r.”?

33. Which equation is equivalent to the relation, “the cost is directly proportional to the number of pencils”?

34. Which equation translates the statement ,the electrical voltage V varies jointly as the current I and the resistance R ?

35. With Php 24, 3 notebooks can be bought at Php 8 each. How many notebooks costing Php 12 each can be bought same amount?

36. Five men can build a hut in 6 days. In how many days can 10 men build the same hut?

37. Manuel can assemble 7 books in 4 minutes. At this rate, how many books can he assemble in 2hrs?

38. What variation is described in the statement “y varies inversely as x”?

39. What type of variation is shown in the relationship between the distance travelled by a car and its allotted time?

40. The length l of the rectangular field varies inversely as its width w. What type of variation is illustrated?