t statistic

can anyone help with question 28 from the CFAI mock exam morning session?

the question gives 2 sample sets of 5 numbers each which are drawn from normally distributed populations with unknown variances. The question than asks what the t statistic to test the hypothesis that the mean difference is equal to 0 is.

i guessed on this one, and the answer key is just all greek symbols with no explanation.

if anyone can explain in laymans terms that would be greta.

thanks

question 29 in the PM is also T statistic and i am equally clueless if anyone has any thoughts.