If the ratio of cost price and selling price is $15:14$, then the loss percent is

Let the Cost Price (CP) be $15x$ and the Selling Price (SP) be $14x$.
Since $\text{CP}>\text{SP}$, there is a loss.

$$\text{Loss}=\text{CP}-\text{SP}=15x-14x=x$$

Now, calculate the Loss Percentage:

$$\text{Loss }\%=\left(\frac{\text{Loss}}{\text{CP}}\right)\times 100\%$$

$$\text{Loss }\%=\left(\frac{x}{15x}\right)\times 100\%=\frac{100}{15}\%=\frac{20}{3}\%=6\frac{2}{3}\%$$

Thus, the loss percent is $6\frac{2}{3}\%$.