Answer:
[tex]\boxed{ (t_d) = \frac{(q - x) }{(w - x_w) + \theta} }[/tex]
Explanation:
[tex]let \: the \: quantity \: of \: the \: tablet \: be \to \: q \\ let \: the \: quantity \: of \: the \: water \: be \to \: w \\let \: the \: amount \: of \:tablet impurities \: be \to \: x_t \\ let \: the \: quantity \: of \: pure \: tablet \: be \to \: (q - x) \\ let \: the \: amount \: of \: heat \: (temp)\: be \to \: \theta\\let \: the \: amount \: of \:water \: impurities \: be \to \: x_w \\ let \: the \: quantity \: of \: pure \: water \: be \to \: (w - x_w) \\ hence \: the \: average \: time \: for \: dissolution : (t_d) \to \\ \boxed{ (t_d) = \frac{(q - x) }{(w - x_w) + \theta} }[/tex]
