Rates

A rate compares two different kinds of quantity, such as litres and minutes or dollars and hours, so \(48\) litres in \(4\) minutes simplifies to \(12\) L/min. In NSW Year 8 maths this subtopic adds decimal amounts and harder unit changes to the rates met in Year 7 (NESA outcome MA4‑RAT‑C‑01).

You will write simplified rates, change a rate per minute into a rate per hour, and convert units such as L/min to kL/h or km/h to m/s, where dividing by \(3.6\) is a short cut. You will compare rates given in different units, find the rate inside a formula like \(C = 30 + 2.4n\), use a net rate when a tank fills and leaks at once, and turn km per litre into litres per \(100\) km for fuel use. It is part of Year 8 Rates and Ratios.