Two pipes; first fills in $t_1$ min, second empties in $t_2$ min ($t_2 t_1$). Together fills in—

Question

Two pipes; first fills in $t_1$ min, second empties in $t_2$ min ($t_2 > t_1$). Together fills in—

Accepted Answer

$\dfrac{t_1 t_2}{t_2 - t_1}$ min

Answer

$\dfrac{t_1 t_2}{t_1 + t_2}$ min

Answer

$\dfrac{t_2 - t_1}{t_1 t_2}$ min

Answer

$t_1 + t_2$ min

Two pipes; first fills in t1t_1t1​ min, second empties in t2t_2t2​ min (t2>t1t_2 > t_1t2​>t1​). Together fills in—