The probability of one arrives within the next 10 minutes when he already been waiting for one jour for a taxi is,
P (X > 70 | X > 60) = P (X > 10) = 1 – P (X ≤ 10) = 1 – {1 – e ^ -((1 / 10) 10)} = e ^ -1
= 0.3679
The probability of one arrives within the next 10 minutes when he already been waiting for one hour for a taxi is 0.3679