What is the single equivalent price increase for two successive price increase of 5% and 8% on an item?

13.4%

Formula used:

Two successive increase of a%, b% = $\frac{100+a}{100} \times \frac{100+b}{100}$

Single price equivalent price increase for 5%, 8% = $\frac{100+5}{100} \times  \frac{100+8}{100}$

                                  = $\frac{11340}{10000}$ = 13.4% increase