In mathematics, a rate is a ratio between two related quantities as a rate of change. If the unit or quantity in respect of which something is changing is not specified, usually the rate is per unit of time.

However, a rate of change can be specified per unit of time, or per unit of length or mass or another quantity. The most common type of rate is “per unit of time”, such as speed, heart rate, and flux. Ratios that have a non-time denominator include exchange rates, literacy rates, and electric field in volts/meter.

Unit rate is a common measure used in our daily life. Where one quantity tells how much quantity in one unit. The quantity may be any thing. The rate is nothing but the ratio between two quantities. The denominator should be 1 while calculating the unit rate.

**Unit Rate: Comparison or ratio between two different quantities with different units.**

**Solved examples of unit rate**

**Question: **If a shop offers you 13 chocolates for Rs. 4.94, what is the unit cost?

**Solution: **

The ratio of cost per unit is

$\frac{Rs.\;4.94}{13\;Chocolates}$

Now, Find the unit cost by dividing the numerator and denominator by 13

The unit cost is Rs. 0.38