A bus uses 18 litres of petrol to travel 90 km. At the same rate of consumption, calculate the amount of petrol needed for a 200 km journey.

The amount of petrol required for each Km

= 18/90
=0.2L

The amount of petrol needed for 200km
=0.2x200
=40L

To find the amount of petrol needed for a 200 km journey, we can set up a proportion based on the rate of consumption.

Let's assume x represents the amount of petrol needed for a 200 km journey.

We know that the bus uses 18 litres of petrol to travel 90 km. So the rate of consumption is 18 litres / 90 km.

We can set up the proportion as follows:

18 litres / 90 km = x litres / 200 km

To solve for x, we can cross-multiply and then divide:

18 * 200 = 90 * x

3600 = 90x

Dividing both sides by 90, we get:

3600 / 90 = x

x = 40

Therefore, the bus would need 40 litres of petrol for a 200 km journey.

To solve this problem, we need to find the amount of petrol needed for a 200 km journey using the given information about the rate of consumption for a 90 km journey.

Let's start by finding the rate of petrol consumption for the bus:

Rate of petrol consumption = Amount of petrol used / Distance traveled

In this case, the amount of petrol used is 18 litres and the distance traveled is 90 km. So, the rate of petrol consumption for the bus is:

Rate of petrol consumption = 18 litres / 90 km

Next, we can use the rate of petrol consumption to calculate the amount of petrol needed for a 200 km journey. We'll assume that the rate of petrol consumption remains constant for different distances.

Amount of petrol needed = Rate of petrol consumption x Distance traveled

In this case, the distance traveled is 200 km. So, the amount of petrol needed for a 200 km journey is:

Amount of petrol needed = (18 litres / 90 km) x 200 km

Simplifying this expression:

Amount of petrol needed = (18 litres / 90 km) x (200 km / 1)

Now, let's do the calculations:

Amount of petrol needed = 18 litres x (200 km / 90 km)

Amount of petrol needed = 18 litres x 2.2222...

Amount of petrol needed ≈ 39.999...

Rounding off to the nearest whole number:

Amount of petrol needed ≈ 40 litres

Therefore, approximately 40 litres of petrol are needed for a 200 km journey at the same rate of consumption.