Quintiles divide a set of variables in how many divisions:
Quantiles are the values of the variable that divide the total number of subjects into ordered groups of equal size. Names such as perceniles, deciles, quintiles, quailes and teiles are used when number of divisions is 100, 10, 5, 4, 3 respectively. Ref: Medical biostatistics, 1st edition pg: 119
3
5
10
15