1. If x is directly proportional to y, and x is 4 when y is 6, what is x when y is 9?
Answer:
Explanation:
x/y = 4/6. When y = 9, x = (4/6) * 9 = 6.
2. If the cost of 5 kg of apples is $10, the cost of 12 kg of apples would be:
Answer:
Explanation:
Directly proportional. Cost/kg = $10/5. For 12 kg: 12 * ($10/5) = $24.
3. As the speed of a car increases, the time taken to cover a certain distance:
Answer:
Explanation:
Speed and time are inversely proportional for a fixed distance.
4. If 6 workers can complete a job in 8 days, 12 workers would complete the same job in:
Answer:
Explanation:
Number of workers and time are inversely proportional. Double the workers, half the time.
5. If a is inversely proportional to b, and a is 10 when b is 5, what is a when b is 10?
Answer:
Explanation:
ab = constant. 10*5 = a*10. Thus, a = 5.
6. If 15 machines produce 150 widgets in 5 hours, 5 machines would produce 150 widgets in:
Answer:
Explanation:
Number of machines and time are inversely proportional for a fixed production.
7. The ratio of x to y is 3:4. If x is 15, then y is:
Answer:
Explanation:
x/y = 3/4. When x = 15, y = (4/3)*15 = 20.
8. If the cost of 8 notebooks is $32, the cost of 10 notebooks is:
Answer:
Explanation:
Cost and number of notebooks are directly proportional.
9. A car traveling at 80 km/h reaches a destination in 5 hours. If it traveled at 100 km/h, it would take:
Answer:
Explanation:
Speed and time are inversely proportional. The journey would be faster.
10. If the product of x and y is constant, then x and y are:
Answer:
Explanation:
If the product is constant, increasing one will decrease the other.
11. If the area of a rectangle is kept constant and the length increases, the breadth:
Answer:
Explanation:
For a fixed area, length and breadth are inversely proportional.
12. A car consumes 5 liters of petrol to travel 100 km. For a journey of 250 km, it would consume:
Answer:
Explanation:
Consumption and distance are directly proportional.
13. 8 pipes fill a tank in 6 hours. 4 pipes would fill the same tank in:
Answer:
Explanation:
Number of pipes and time are inversely proportional.
14. If 7 bags of rice weigh 49 kg, 10 bags would weigh:
Answer:
Explanation:
Weight is directly proportional to the number of bags.
15. If y = k/x (where k is a constant), then y and x are:
Answer:
Explanation:
As the value of x increases, y decreases for a constant k.
16. A fan consumes 50 watts in 1 hour. For 4 hours of usage, it would consume:
Answer:
Explanation:
Power consumption and time are directly proportional.
17. If a decreases as b increases, then a and b are:
Answer:
Explanation:
Increase in one results in a decrease in the other.
18. If 9 pens cost $27, 15 pens would cost:
Answer:
Explanation:
Cost and number of pens are directly proportional.
19. A journey of 600 km is completed in 8 hours. The speed of the vehicle is:
Answer:
Explanation:
Speed = Distance/Time.
20. If 3x = 2y, then x and y are:
Answer:
Explanation:
The ratio is constant.