The dimensions of the tank are 50 cm by 32 cm by 20 cm. The tank is full of water and sand.
The ratio of the volume of water to the volume of sand is 5:1
Work out the number of litres of water in the tank.

The total cost of anja’s trip to the dentist was $628.35. she paid a flat fee of $89.95 which included the checkup and cleaning and then had 4 cavities filled, each of which cost the same amount. which shows the correct equation and value of x, the cost of each cavity filling?