A car is drive z km a day but not used at the weekend. It does g km per litre of petrol. Find the cost of petrol for the week in pounds, if petrol costs v?

Question

Really find these worded equations hard. Please help!!!! Thank you so much. XXX

Answer 1

Let's use numbers to start.

 

 

If a car is driven 50 km/day during the week, that's 5(50) = 250 km/week. With z km/day, that's 5z km/week.

 

If the car does 25 km/litre, that's 250/25 = 10 litres/week. Since the car does g km/litre, that's 5z/g litres per week.

 

Now, if petrol is $2 per litre, you're paying 2(10) = $20/week in petrol. Since petrol is $v, you are paying 5zv/g. We put the variables in alphabetical order in either the numerator or denominator, so for the week, you spent 5vz/g in petrol.