Question

Find the growth of the plant in 20 days (in ft) if its growth is directly proportional to the time taken.

• A. 60

Answer 1

The correct option is A 60
We have to find the growth of a plant in 20 days.

First, we have to find its growth for one day and then multiply the value with 20.

Let us represent growth by "y" and time by "x".


So,
$\text{Growth in 1 day}=\frac{y}{x}$
$=\frac{30}{10}$
$=3$

$\text{Number of days,}x=20$

$\text{So, when}x=20$,
$\text{Growth in 1 day =}\frac{y}{20}$
$\Rightarrow 3=\frac{y}{20}$
$\Rightarrow y=20\times 3$
$\Rightarrow y=60$

∴ The plant grows by 60 ft in 20 days.