Exercise 13.2
Q1. Which of the following are in inverse proportion?
(i) The number of workers on a job and the time to complete the job.
(ii) The time taken for a journey and the distance travelled in a uniform speed.
(iii) Area of cultivated land and the crop harvested.
(iv) The time taken for a fixed journey and the speed of the vehicle.
(v) The population of a country and the area of land per person.
Solution:
(i) Numbers of workers on a job and time always be in inverse proportion because when we increase in workers time reduces and when we reduce in workers time it take more time.
(ii) The time taken and distance are in direct proportion because if we increase in time it covers more distance. Hence both quantities increase together.
(iii) As area will be cultivated as more crops will be harvested. So these are direct proportion.
(iv) Time and speed always be in inverse proportion. As we increase the time we have to reduce the speed to cover a fixed distance. Similarly we see that if we increase the speed time reduces automatically.
(v) If population is increased area land will be short to live. Therefore these both quantity are in inverse proportion.
Q2. In a Television game show, the prize money of Rs 1,00,000 is to be divided equally amongst the winners. Complete the following table and find whether the prize money given to an individual winner is directly or inversely proportional to the number of winners?
Solution: Prize will be distributed to winner in inverse proportion.
As both quantities are in inverse proportion.
Suppose the table has …
Q3. Rehman is making a wheel using spokes. He wants to fix equal spokes in such a way that the angles between any pair of consecutive spokes are equal. Help him by completing the following table.
Solution:
The relation between spokes and angle between consecutive spokes are in inverse proportion.
Therefore, X1Y1 = X2Y2
Q4. If a box of sweets is divided among 24 children, they will get 5 sweets each. How many would each get, if the number of the children is reduced by 4?
Solution:
According to question we have the table like this
