Question

A car uses 25 litres of fuel when travelling 355 kilometers. How far can it travel with 42 liters of fuel

Answer 1

Answer:

$\boxed {\boxed {\sf 596.4 \ kilometers}}$

Step-by-step explanation:

Let's create a proportion using this setup.

$\frac {liters}{kilometers} = \frac{liters}{kilometers}$

We know that 25 liters are used for 355 kilometers.

$\frac {25 \ liters}{355 \ kilometers} = \frac{liters}{kilometers}$

We don't know how many kilometers are used with 42 liters. Therefore we say x kilometers are used for 42 liters.

$\frac {25 \ liters}{355 \ kilometers} = \frac{42 \ liters}{x \ kilometers}$

$\frac {25 }{355 } = \frac{42 }{x}$

Cross multiply. Multiply the first numerator by the second denominator, then the first denominator by the second numerator.

$25*x=42*355$

$25x=14910$

Since we are solving for x, we need to isolate the variable. x is being multiplied by 25. The inverse of multiplication is division, so divide both sides by 25.

$\frac{25x}{25}=\frac {14910}{25}$

$x=596.4$

The car can travel 596.4 kilometers with 42 liters of fuel.