Advertisements
Advertisements
Question
Which of the following quantities vary directly with each other?
(i) Number of articles (x) and their price (y).
(ii) Weight of articles (x) and their cost (y).
(iii) Distance x and time y, speed remaining the same.
(iv) Wages (y) and number of hours (x) of work.
(v) Speed (x) and time (y) (distance covered remaining the same).
(vi) Area of a land (x) and its cost (y).
Advertisements
Solution
(i) The number of articles is directly related to the price. Therefore, they will vary directly with each other.
(ii) The number of articles is directly related to the weight of the articles. Therefore, they will vary directly with each other.
(iii) Speed is constant. Therefore, distance and time does not vary directly.
(iv) The number of hours is directly related to the wages. Therefore, it is a direct variation.
(v) Distance is constant. Therefore, speed and time does not vary directly.
(vi) If the area of a land is large, its cost will also be high. Thus, it is a direct variation.
Thus, the respective values in (i), (ii), (iv) and (vi) vary directly with each other.
RELATED QUESTIONS
A car is travelling at the average speed of 50 km/hr. How much distance would it travel in 12 minutes?
The cost of 97 metre of cloth is Rs 242.50. What length of this can be purchased for Rs 302.50?
In 15 days, the earth picks up 1.2 × 108 kg of dust from the atmosphere. In how many days it will pick up 4.8 × 108 kg of dust?
Both u and v vary directly with each other. When u is 10, v is 15, which of the following is not a possible pair of corresponding values of u and v?
Write whether the following statement vary directly, vary inversely with each other, or neither of the two.
Distance travelled by an auto-rickshaw and time taken.
Write whether the following statement vary directly, vary inversely with each other, or neither of the two.
Area of land and its cost.
A volleyball court is in a rectangular shape and its dimensions are directly proportional to the dimensions of the swimming pool given below. Find the width of the pool.

Here is a keyboard of a harmonium: What is the ratio of black keys to all keys on the given keyboard.
Kusum always forgets how to convert miles to kilometres and back again. However she remembers that her car’s speedometer shows both miles and kilometres. She knows that travelling 50 miles per hour is same as travelling 80 kilometres per hour. To cover a distance of 200 km, how many miles Kusum would have to go?
The students of Anju’s class sold posters to raise money. Anju wanted to create a ratio for finding the amount of money her class would make for different numbers of posters sold. She knew they could raise Rs 250 for every 60 posters sold.
- How much money would Anju’s class make for selling 102 posters?
- Could Anju’s class raise exactly Rs 2,000? If so, how many posters would they need to sell? If not, why?
