There are twelve possible outcomes in the sample space:

{H1, H2, H3, H4 H5, H6, T1, T2, T3, T4, T5, T6}

The event space has two possible outcomes: {T1, T2}

The probability of flipping tails and a number less than 3 is $\displaystyle\frac{{2}}{{12}}\usepackage{cmbright}\Huge\$ , or $\displaystyle\frac{{1}}{{6}}.\usepackage{cmbright}\Huge\$