S K Gupta and Anubhuti Gangal Solutions for Chapter: Direct and Inverse Variations, Exercise 1: Exercise 9(A)

In which of the following, $x$ and $y$ vary directly with each other. For each direct variation, state the constant of variation.

The height to which a ballon with hydrogen gas rises in the air varies directly as time. Given below are some observations about the time and corresponding height of the ballon (in meters). Find the missing terms in the table.

If d varies directly as 't', and, if $d=4$ when $t=9$, find $\text{'}d\text{'}$, when $t=21$.

The mass of a uniform copper bar varies directly as its length. If a bar $40 cm$ long has a mass of approximately $420 g$, find the mass of a bar $136 cm$ long.

A fish with mass of $3 kg$ causes a fishing pole to bend $9 cm$. If the amount of bending varies directly as the mass, how much will the pole bend for a $2 kg$ fish?

At a party, $8$ bottles of soft drink are served for every batch of $5$ children. How many bottles would be served if $40$ children were present at the party?

Harsh takes $150$ steps in walking a distance of $125$ meters. What distance would he cover in $360$ steps?

The second class railway fare for $240 km$ of journey is $₹15.00$. What would be the fare for a journey of $139.2 km?$ Assume that the fare varies directly as the length of a journey.