A certain pendulum clock with a 12 h dial happens to gain 1.0 min/day. After setting the lock to the correct time, how long must one wait until it again indicates the correct time ?

Q: A certain pendulum clock with a 12 h dial happens to gain 1.0 min/day. After setting the lock to the correct time, how long must one wait until it again indicates the correct time ?

(a) 720 min

(b) 720 days

(c) 60 days

(d) 12 min

Ans: (b)