Question

There is a relationship between the flight time of the drone ($t$, in min) and the cost of the drone ($c$, in $\$$); the higher the flight time, the higher the cost of the drone.

Flight time ($t$, in min)	$20$	$30$	$40$
Cost of drone ($c$, in $)	$400$	$600$	$800$

Identify the equation that defines the relation between $(t$) and $\left(c\right)$.

• A. $c=25÷t$
• B. $c=20t$
• C. $c=20÷t$
• D. $c=25t$

Answer 1

The correct option is B $c=20t$

To find which option defines the correct relationship between the flight time of the drone ($t$, in min) and the cost of the drone ($c$, in $\$$), we will substitute the value of $t$ given in the table to find $c$ from the equation. Then we will match it with the correct value of $c$ from the table.

Option A:
Equation: $c=25÷t$
When $t=20$,
$c=25÷20$
$c=1.25$
However, the value of $c$ in the table is $400$.
Option A is incorrect.


Option B:
Equation: $c=25t$
When $t=20$,
$c=25\times 20$
$c=500$
However, the value of $c$ in the table is $400$.
Option B is incorrect.

Option C:
Equation: $c=20÷t$
When $t=20$,
$c=20÷20$
$c=1$
However, the value of $c$ in the table is $400$.
Option C is incorrect.

Option D:
Equation: $c=20t$
When $t=20$,
$c=20\times 20$
$c=400$

When $t=30$,
$c=20\times 30$
$c=600$

When $t=40$,
$c=20\times 40$
$c=800$

Option D is correct.