SOLUTION: Mr chows car consumes petrol at an average rate of 8 litres daily. before Mr Chow begins his journey he top up the petrol in his car to 100 litres. given that he will next top of t

Question 1126439: Mr chows car consumes petrol at an average rate of 8 litres daily. before Mr Chow begins his journey he top up the petrol in his car to 100 litres. given that he will next top of the petrol in his car when there are 20 litres left, form an in equality and solve it to find the maximum number of days he can travel before he has to top up the petrol in car.
Answer by Theo(13342) (Show Source): You can put this solution on YOUR website!
he starts with 100 liters.
he will top up when there are 20 liters left in the tank.
that means he will top up when he consumes 80 liters.
if he uses 8 liters a day, then he can go 10 days before topping up again.

your formula can be:

20 = 100 - 8x

x is the number of days before he needs to top up again.

solve this equation for x as follows:
add 8x to both sides of the equation and subtract 20 from both sides of the equation to get:
8x = 100 - 20
combine like terms to get 8x = 80
divide both sides by 8 to get x = 10.

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