Question

A machine takes $2$ litres of petrol to start and then $3$ litres per hour while running. If the equation thus formed is of the form $ax+by+c=0$. What is the value of $c$, if x denotes the number of hours machine had run?

• A. $3$
• B. $-2$
• C. $2$
• D. $1$

Answer 1

Answer: (B)

$-2$

Amount of petrol used $=y$
Number of hours for which machine will work $=x$
$\therefore y=3x+2$
$\Rightarrow y-3x-2=0$
$\Rightarrow -3x+y-2=0$

Comparing this with equation $ax+by+c=0$, we get
$a=-3,b=1,c=-2$