The experimental probability is given by the following formula
[tex]\text{experimental probability=}\frac{successful\text{ tries}}{\text{total number of tries}}[/tex]In our case, the total number of tries is 10 and the successful number of tries is 3 (landing on tails); thus,
[tex]\Rightarrow\text{experimental probability}=\frac{3}{10}[/tex]The answer is 3/10