Contents of Choices

Choices

t
${\frac{{1}}{{2}}}$ t + ${\frac{{1}}{{2}}}$ r
${\frac{{1}}{{\frac{1}{t}+\frac{1}{r}}% }}$ $\correctchoice$
r
${\frac{{1}}{{\frac{1}{t}+\frac{1}{r}}}}$ + 1